CBSE Class 10

CBSE Sample Papers for Class 10 Science Paper 6

These Sample papers are part of CBSE Sample Papers for Class 10 Science. Here we have given CBSE Sample Papers for Class 10 Science Paper 6.

Time allowed: 3 hours
Maximum marks : 80

General Instructions

• The question paper comprises two sections, A and B. You are to attempt both the sections.
• All questions are compulsory.
• All questions of Section-A and B are to be attempted separately.
• There is an internal choice in two questions of three marks each and one question of five marks.
• Question numbers 1 and 2 in Section-A are one mark question. They are to be answered in one word or in one sentence.
• Question numbers 3 to 5 in Section-A are two marks questions. These are to be answered in 30 words each.
• Question numbers 6 to 15 in Section-A are three marks questions. These are to be answered in about 50 words each.
• Question numbers 16 to 21 in Section-A are 5 mark questions. These are to be answered in 70 words each.
• Question numbers 22 to 27 in Section-B are based on practical skills. Each question is a two marks question. These are to be answered in brief.

SECTION – A

Question. 1.
What are biodegradable substances ? Give two examples.

Question. 2.
What does the peripheral nervous system consist of ?

Question. 3.
What are isotopes ?

Question. 4.
What is Snell’s law of refraction ?

Question. 5.
Compare natural and artificial ecosystems ?

Question. 6.
What is the principle on which an electric motor works ? What are the special features of commercial electric motors ?
OR
A wire of length L and resistance R is stretched so that its length is doubled and the area of cross-section is halved. How will its :
(a) resistance change ?
(b) resistivity change ?
Justify your answer in each case.

Question. 7.
List the properties of magnetic lines of force.

Question. 8.
What is amalgam ? What are the benefits of alloying ?

Question. 9.
Is it necessary to mention the physical states of the reactants and products in a chemical equation. Explain with an example.

Question. 10.
Describe the ovary of the flower with a labelled diagram.
OR
What is the role of seminal vesicles and prostrate gland ?

Question. 11.
How does phototropism occur in plants ?

Question. 12.
If the image formed by a lens for all positions of an object placed in front of it is always erect and diminished what kind of lens is it? Justify with a ray diagram. If the power of the lens is -10 D, what is its focal length?

Question. 13.
Show the formation of chlorine molecule using electron dot structure.
OR
What is the role of metal of reagents written on arrows in the given chemical reactions ?

Question. 14.
Why should we use our resources judiciously ?

Question. 15.
Why are platelets needed by our body ?

Question. 16.
Name the type of mirror used in the following situations :
(a) Headlights of a car.
(b) Side/rear-view mirror of a vehicle.
(c) Solar furnace.
Support your answer with reason.

Question. 17.
How could the Modem Periodic Table remove various anomalies of Mendeleev’s Periodic Table ?
OR
What were the limitations of Mendeleev’s periodic table ?

Question. 18.
What is the response of plants to stimuli known as ? Describe the different types of these movements.

Question. 19.
What is Ohm’s law ? Draw the circuit for verifying Ohm’s law. If you draw a graph between the potential difference and the current flowing through a metallic conductor, what kind of curve will you get ? Explain how would you use this graph to determine the resistance of the conductor ?

Question. 20.
Discuss the properties of ionic compounds with regard to their melting and boiling point and conduction of electricity.

Question. 21.
What is hydroelectricity or hydel electricity ? What should one has to keep in mind while constructing a dam ?
OR
What is the importance of forest as a resource ? What are the causes of deforestation ?

SECTION – B

Question. 22.
Why does silver turn black when exposed to air ?

Question. 23.
What happens when dry slaked lime [Ca (OH)₂] reacts with chlorine ? What is the product used for ?

Question. 24.
Draw a labelled diagram of the human brain. What is the function of the medulla ?

Question. 25.
Which of the following actions we should adopt and why ?

(a) Taking a bus or using your personal vehicle.
(b) Using ordinary bulbs or LED bulbs in your homes.
(c) Taking the stairs or using the lift.
(d) Wearing extra woollen clothes or using the heater.

Question. 26.
Find the least count of a milliammeter in which there are 20 divisions between 400 mA and 500 mA marks.
OR
While experimentally verifying Ohm’s law, a student observed that the pointer of the voltmeter coincides with 15th division when the voltmeter has a least count of 0.05 V. Find the observed reading of voltmeter.

Question. 27.
Raju places a candle flame at a distance of about 60 cm from a convex lens of focal length 10 cm and focuses the image of the flame on a screen. Then he slowly moves the flame towards the lens and each time gets the image on the screen.

(a) In which direction from the lens, does he move the screen to focus the image ?
(b) What is the change in the size of the image ?
(c) How does the intensity of the flame change as the flame moves towards the lens ?
(d) At what point approximately between the flame and the lens will the image be inverted and of the same size ?

ANSWERS

SECTION – A

Answer. 1.
Biodegradable substances are those substances that can be broken down by biological processes. Some examples are remains of plants and animals and vegetable wastes that our houses produce daily.

Answer. 2.
The peripheral nervous system consists of the cranial nerves and the spinal nerves. While cranial nerves arise from the brain, the spinal nerves arise from the spinal cord.

Answer. 3.
Isotopes are atoms of elements having different mass numbers or atomic mass but the same atomic numbers.

Answer. 4.
According to Snell’s law of refraction, the ratio of sine of angle of incidence to the sine of angle of refraction is constant for a given pair of media.
sine of angle of incidence / sine of angle of refraction = constant
OR
\(\frac { sin\quad i }{ sin\quad r } \) = constant = n
This constant is called refractive index.

Answer. 5.
Natural ecosystems are the ones found in nature such as forests, ponds and lakes. Artificial ecosystems are man-made such as gardens and crop-fields.

Answer. 6.
A motor works on the principle that when a rectangular coil is placed in a magnetic field and current is passed through it, a force acts on the coil which rotates it continuously. When the coil rotates, the shaft attached to it also rotates. In this way the electrical energy supplied to the motor is converted into the mechanical energy of rotation. Electric motor is an important component in electric fans, refrigerators, mixers, washing machines, computers and mp3 players.
The commercial motors use :
(a) An electromagnet in place of the permanent magnet.
(b) Large number of turns of the conducting wire in the current-carrying coil.
(c) A soft iron core on which the coil is wound and the coils is called an armature. The soft iron core becomes magnetised and increases the strength of magnetic field. This makes the motor more powerful.
OR
(a) Here, length is doubled and area of cross-section is halved. Thus, a wire of length l and area of cross-section A becomes a wire of length 2l and area of cross-section \(\frac { A }{ 2 }\)

i.e., resistance becomes four times.
Resistivity of a substance does not depend on its length or area of cross-section. It depends on the nature of the material and temperature. Hence, there is no change.

Answer. 7.
Properties of magnetic field lines :

1. Magnetic field lines follow the direction from the North Pole to the South Pole.
2. Magnetic field lines always form closed circular loops.
3. Magnetic field lines do not cross one another.
4. Closer the field lines; stronger is the magnetic field and vice-versa.
5. Magnetic field lines are closer near the poles; which shows greater strength of magnetic field near the poles.

Answer. 8.
Amalgam is an alloy in which one of the constituent metal is mercury. Alloying is a good method of improving the properties of a metal. An alloy can have the properties of its constituents. An alloy is a homogeneous mixture of two or more metals or a metal and a non-metal. The electrical conductivity and melting point of an alloy is less than that of pure metals. Iron is a widely used metal. Usually iron in its pure state is very soft and easily stretched. When mixed with a little carbon it becomes hard and strong. Similarly when iron is mixed with nickel and chromium it produces stainless steel which is hard and resistant to rust. Solder, an alloy of lead and tin has a low melting point and is used for welding electrical wires together. Brass, an alloy of copper and zinc and bronze, an alloy of copper and tin are not good conductors of electricity though copper is used for making electrical circuits.

Answer. 9.
A chemical equation can be made more informative by mentioning the physical states of the reactants and products along with their chemical formulae. The gaseous, liquid, queous, and solid states of the reactants and products are represented by the notations, (g), (1), (aq) and (s) respectively. The word aqueous is written if the reactant or product s present as a solution in water. When we use the symbol (g) with H₂O it means in the reaction water is used as steam.
Example : 3Fe(s) + 4H₂O(g) → Fe₃O₄(s) + 4H₂(g)
In the above example, Fe in the solid state reacts with water in steam form and forms iron oxide in solid form and releases hydrogen gas.

Answer. 10.
The carpel is the female reproductive part of the flower which is present in the centre of the flower. It ^ consists of three parts. The upper part which is sticky and is called the stigma, the middle elongated part is called the style and the swollen bottom part is called ovary. The ovary contains the ovules and each ovule has an egg inside. The male germ-cell produced by the pollen grain fuses with the female germ cell in the ovule. This is called fertilisation and it results in the formation of the zygote. This zygote grows into a new plant.

The sperms are formed in the testes which are located outside the abdominal cavity. The sperms formed are delivered through the vas deferens which unites with a tube coming from the urinary bladder. The urethra is thus a common passage for both the sperms and urine. Seminal vesicles and prostate gland are two glands associated with the male reproductive system. These glands produce secretions that are added to the sperm during its movement through the vas deferens. The secretions provide a fluid medium to facilitate easy movement of the sperms and they also nourish the moving sperms. It is primarily the tail of the sperm which helps it in swimming in this fluid medium.

Answer. 11.
Phototropism means the response of plant parts towards sunlight. Here sunlight is the stimulus, while the shoot system responds positively to sunlight the root system responds negatively to sunlight. Different plant hormones help to coordinate growth, development and responses to the environment. They are synthesised at places away from where they act and simply diffuse to the area of action. When growing plants detect light, a hormone called auxin which is synthesised at root tips helps the cells to grow longer. When light is coming from one side of the plant, auxin diffuses towards the shady side of the shoot. This concentration of the auxin stimulates the cells to grow longer on the side of the shoot which is away from light. Thus, the plant appears to bend towards light.

Answer. 12.
If the image formed by a lens for all positions of an object placed in front of it is always erect and diminished, it is a concave lens.

As f has negative value so, it is a concave lens.

Answer. 13.
Chlorine atom has the atomic number 17. This means it has 17 electrons too. Its electronic configuration is 2,8 and 7. So it has a valency of 7. Now 2 chlorine atoms combine to form a chlorine molecule. Each atom is 1 short of the stable configuration. This is set right by sharing 1 electron each between the 2 atoms. Thus a single covalent bond is formed between the 2 chlorine atoms.

OR
(a) Ni acts as a catalyst.
(b) Concentrated H₂SO₄ acts as a catalyst.
(c) Alkaline KMnO₄ acts as an oxidising agent.

Answer. 14.
All the things we use or consume like food, clothes, our shelter, books, toys, furniture, tools and vehicles are obtained from resources on this earth. The only thing we get from outside is the energy from the sun. This too is processed by the living organisms and various physical and chemical processes on the earth before we can use it. We should use resources judiciously because they are limited. We have an ever-increasing human population due to improved health care and this has brought about an increased demand for all the resources. The management of natural resources requires a long-time perspective so that they will last for the future generations and will not be exploited over a short period of time. Resource management must be focussed on an equitable distribution of resources so that it is not just a handful of rich and powerful people who benefit from this. In addition, when we extract these resources we must ensure a safe disposal of the wastes too. This is called sustainable natural resource management.

Answer. 15.
Platelets or thrombocytes are one of the constituents of blood the other two being the red blood corpuscles or erythrocytes and white blood corpuscles or leucocytes. Whenever there is an injury in the body bleeding starts. The body cannot afford to lose blood. In addition, leakage of blood leads to a drop in pressure which affects the pumping of the heart. To avoid this the body immediately informs the platelets to reach the site of injury. The platelets that keep circulating in the body quickly reach the site of bleeding and form a barrier or plug which stops the bleeding. That is why platelets are needed by our body.

Answer. 16.
(a) Concave mirror (b) Convex mirror (c) Concave mirror.
Explanation:

(a) Concave mirror is used in the headlights of a car. This is because concave mirrors can produce powerful parallel beam of light when the light source is placed at their principal focus. This powerful beam of light helps us to see things upto a considerable distance in the darkness of night.
(b) Convex mirror is used in side/rear view mirror of a vehicle. Convex mirrors give a virtual, erect, and diminished image of the objects placed in front of it. Because of this, they have a wide field of view. It enables the driver to see most of the traffic behind him/her.
(c) Concave mirrors are convergent mirrors. That is why they are used to construct solar furnaces. When solar furnace is placed at focus of concave mirror, sun rays after reflection from its surface gets converged at focus with much intense heat and solar furnace gets very hot.

Answer. 17.
Modem Periodic Table removes various anomalies of Mendeleev’s Periodic Table on the following points :

1. Position of isotopes : As Modem Periodic Table is based on atomic number, isotopes can be placed at one place in same group in Modem Periodic Table.
2. Anomalous Position of some pair of elements: In Mendeleev periodic table, some of the elements having higher atomic mass are placed before the elements having lower atomic mass. This defect of Mendeleev periodic table was overcome in Modem periodic table since it is based on atomic numbers.
3. Prediction of new elements: In long form of periodic table, the position and properties of new elements can be predicted easily on the basis of their atomic numbers or electronic configuration.

OR
The limitations of Mendeleev’s periodic table are as follows :

1. Hydrogen could not be given a fixed position. Electronic configuration of hydrogen is similar to alkali metals. It was able to combine with halogens, oxygen and sulphur to form compounds having similar formulae. Hydrogen could also exist as diatomic molecules just like halogens and could combine with metals and non-metals to form covalent compounds.
2. There was confusion regarding isotopes. Isotopes were discovered long after Mendeleev had done his periodic classification. Isotopes of an element have similar chemical properties but different atomic masses.
3. Atomic masses do not increase in a regular manner in going from one element to the next. Hence it was not possible to predict how many elements could be discovered between two elements.

Answer. 18.
Plants show two different kinds of movements one dependent on growth and the other independent of growth. The response of plants to stimuli is called trophic movements. The word tropism means response to stimuli. Though plants do not have an elaborate nervous system they do respond to a variety of stimuli. Response of plants to the stimulus of light is known as phototropism. The stem and its parts are phototrophic. The response of plants to water is known as hydrotropism. Roots respond to the presence of water by growing towards it. Response to gravitational pull is called geotropism. Roots are geotropic. Response of plants or their parts to the stimulus of touch is called thigmotropism. Some plants like the pea plant are very tender and climb up on supports for their growth. When their tendrils come in contact with any support, the tendrils immediately curl round the support and get a good grip.

Answer. 19.
Ohm’s law states that the electric current flowing through a metallic wire is directly proportional to the potential difference V across its ends provided its temperature remains the same.
In other words V α I
or
V/I = constant = R
or
V = I × R
Where R is a constant for a given metallic wire and is called its resistance.

If a graph is drawn between the potential difference (V) and current (I) the graph is found to be a straight line passing through the origin. This clearly shows that current is directly proportional to the potential difference. So the ratio V/I is a constant. This is the resistance of the conductor. The gradient of the straight line graph represents the resistance of the conductor.

Answer. 20.
Ionic compounds are formed by the transfer of electrons from one atom to another in an effort to get the stable electronic configuration in their outermost shell. The bond formed is called electrovalent bond and the atoms in that are either positive or negative ions. These ions are held together by strong forces of attraction. Hence ionic compounds are usually solids.

1. Ionic compounds have high melting and boiling points this means a lot of energy is required to break the strong inter-ionic attraction.
2. A solution of ionic compounds contains ions which move to the oppositely charged electrodes when current passes through the solution. Ionic compounds do not conduct electricity in the solid state as ions cannot move about. Ionic compounds conduct electricity in the molten state as the electrostatic forces between the ions is overcome by the heat.

Answer. 21.
Hydroelectricity or hydel electricity is the generation of electricity using the power of water. It is a means to generate electricity either from the kinetic energy of flowing water or the potential energy of falling water. In our country we primarily focus on storing huge quantities of water by building dams across rivers. The water from the high levels in the dam is carried through pipes to a turbine at the bottom of the dam. As rains regularly fill up the dams one need not worry about the generation of electricity. However while constructing dams one has to keep in mind a few things.

1. Not to affect large areas of agricultural land.
2. To safeguard the human habitation around the dam.
3. To ensure that vegetation is not submerged under water in the dams giving rise to air pollution on rotting.

OR
Forests are an important natural resource due to following reasons :

1. Forests provide us wood, dry fruits, spices, gums, resins, dyes, tannins and various products like honey, camphour, rubber etc.
2. The roots of trees hold the soil firmly preventing soil erosion.
3. It absorbs carbon dioxide from atmosphere and release oxygen which is life supporter.
4. It absorbs carbon dioxide which is a greenhouse gas thus plays an important role in reducing global warming.
5. It increases frequency of rainfall and regulates water cycle.
6. It serves as a shelter for wild life.

Causes of deforestation are :

1. Large scale deforestation for demand of wood, timber as raw materials for industries, domestic purposes etc.
2. Construction of dams, reservoirs, roads, railways.
3. Setting up of factories and industries.
4. Construction of big apartments to provide space to the growing population.
5. Shifting cultivation for agriculture.
6. Over-grazing by livestock.

SECTION – B

Answer. 22.
Silver turns black when exposed to air because it undergoes oxidation and forms silver oxide.
2Ag(s) + O₂ (g) → 2AgO(s)

Answer. 23.
When dry slaked lime Ca(OH)2 reacts with chlorine it forms bleaching powder.
Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂ O
Bleaching powder is used as a bleaching agent in textile industry and laundry units as a disinfectant, as an oxidising agent in chemical industries and in bleaching wood pulp in paper factories.

Answer. 24.
The medulla controls several involuntary actions like salivation, vomiting, blinking of the eye and blood pressure.

Answer. 25.

(a) We should take the public transport because it would save fuel.
(b) We should use LED bulbs in my house because it will help conserve electricity and bring down the electric bills.
(c) We should take the stairs because it would be good physical exercise for us and we can save on electricity.
(d) We should prefer wearing extra woollen clothes to using the heater because this saves electricity.

Answer. 26.

Answer. 27.

(a) further away from the lens to focus the image on the screen.
(b) The image increases in size.
(c) As the flame moves towards the lens, the intensity of the image decreases.
(d) When the flame is placed 20 cm from the lens on its left side we get an inverted and same size image.

We hope the CBSE Sample Papers for Class 10 Science paper 6 help you. If you have any query regarding CBSE Sample Papers for Class 10 Science paper 6, drop a comment below and we will get back to you at the earliest.

CBSE Sample Papers for Class 10 English Communicative Set 4

These Sample papers are part of CBSE Sample Papers for Class 10 English Communicative. Here we have given CBSE Sample Papers for Class 10 English Communicative Set 4

Time allowed: 3 hours
Maximum marks: 80

General Instructions

❖ The question papers divided into three sections :
Section A : Reading 20 marks
Section B : Writing and Grammar 30 marks
Section C : Literature 30 marks
❖ All questions are compulsory.
❖ You may attempt any section at a time.
❖ All questions of that particular section must be attempted in the correct order.

SECTION-A : READING
(Attempt all question from this section)

Question 1.
Read the passage given below and answer the questions that follow:
1. Over the centuries, people have created many rituals to accompany the consumption of their favourite drinks—tea and coffee. Just think of the Japanese tea ceremony, British afternoon tea or the morning coffee ritual in countless societies. Why are these drinks so popular ? The answer is their secret ingredient- caffeine. In the modem world, the new caffeine ‘delivery systems’ are canned ‘energy’ drinks. The more modem our world gets, the more we seem to need caffeine. People have known for years that caffeinated drinks make you less tired and more alert. This dual power of caffeine to counteract physical fatigue and increase alertness is a part of the reason why it is the world’s most popular mood-altering drug.
2. Most people don’t think twice about their caffeine intake. However, it raises blood pressure and thus increases the risk of heart diseases. So, the widespread use of caffeine is now a cause for concern among scientists and public health authorities. On the other hand, much of the research suggests that caffeine may have benefits for human health. Studies have shown it helps to relieve pain, reduces asthma symptoms and increases reaction speed. Despite this, a study in Ireland recommended that children and pregnant women, among other groups, shouldn’t drink energy drinks.
3. ‘For most of human existence, the pattern of sleeping and waking has followed sunrise and sunset,’ explains Charles Czeisler, a neuroscientist at Harvard Medical School. ‘Electric lights’ and caffeinated food and drinks allowed people to follow a work schedule set by the clock, not by daylight or the natural sleep cycle’.
4. ‘Caffeine helps people to override the human rhythm that is in all of us,’ says Czeisler. ‘Nevertheless/ he says solemnly, ‘there is a heavy, heavy price to pay for all this extra wakefulness.’ Without adequate sleep – the conventional eight hours out of each 24 is about right- the human body will not function at its best, physically, mentally or emotionally, the doctor says.
5. According to Czeisler, the modem craving for caffeine is a ‘Catch 22 situation’. ‘The main reason that people want caffeine is to stay awake/ he says. ‘But the main reason that people can’t stay awake is they don’t get enough regular sleep because they use caffeine.’

1.1. Attempt any eight of the following questions on the basis of the passage you have read: [1 x 8 = 8]
(i) What rituals did people create to drink tea or coffee and also give example ?
(ii) Why are these drinks popular in many societies ?
(iii) How is caffeine delivered in the modern times ?
(iv) Why is caffeine the most mood altering drug ?
(v) What are the contradicting effect of caffeine on health ?
(vi) Who shouldn’t consume caffeine ?
(vii) How has caffeine and electric light altered the life pattern ?
(viii) What is the heavy price we might pay with caffeine dominating our lifestyles and inadequate sleep ?
(ix) Why is the ‘Catch 22’ situation mentioned in the passage ?

Question 2.
Read the passage given below and answer the questions that follow : [12]
1. Peru’s Inca Indians first grew potatoes in the Andes Mountains in about 200 BC. Spanish conquistadors brought potatoes to Europe and colonists brought them to America. Potatoes are fourth on the list of the world’s food staples-after wheat, com and rice.
2. Today, Americans consume about 140 pounds of potatoes per person every year, while Europeans eat twice as many. One of our favourite ways to eat potatoes is in the form of potato chips. While Benjamin Franklin was the American ambassador to France, he went to a banquet where potatoes were prepared in 20 different ways. Thomas Jefferson, who succeeded Franklin as our French ambassador, brought the recipe for thick-cut, French fried potatoes to America. He served French fries to guests at the White House in 1802 and at his home, Monticello.
3. A Native American chef named George Crum created the first potato chips on August 24,1853, at Moon Lake Lodge in Saratoga, New York. He became angry when a diner complained that his French fries were too thick, so he sliced the potatoes as thin as possible, making them too thin and crisp to eat with a fork. The diner loved them and potato chips were bom. In 1860, Chef Crum opened his own restaurant and offered a basket of potato chips on every table.
4. Joe “Spud” Murphy and Seamus Burke produced the world’s first seasoned crisps, cheese and onion and salt and vinegar chips, in the 1950s in Ireland. In the United Kingdom and Ireland, crisps are what we, in the United States, call potato chips, while their chips refer to our French fries. Ketchup-flavoured chips are popular in the Middle East and Canada. Seaweed-flavoured chips are popular in Asia, and chicken-flavoured chips are popular in Mexico.
5. Other flavours from around the world include : paprika, pickled onion, bearnaise, meat pie, chili crab, salmon teriyaki, borscht, Caesar salad, roasted sausage, firecracker lobster, roast ox, haggis and black pepper, olive and spaghetti. About 27 pounds of potato chips are produced from 100 pounds of potatoes. Americans consume 2-4 billion pounds of potato chips every year and spend more than $ 7 billion a year on them.

2.1 On the basis of your reading of the passage, answer any four of the following questions in about 30-40 words each: [2 x 4 = 8]
(i) How did potatoes reach Europe and who were the first to grow potatoes ?
(ii) How did potatoes French fries became so popular in America and when ?
(iii) How can you say that potatoes are favourite in America and Europe ?
(iv) How were potato chips born ?
(v) In what manner has potato chips or fries become so important ?

2.2 On the basis of your reading of the passage, fill any two of the following blanks with
appropriate words / phrases. [1 x 2 = 2]
(i) Potatoes are fourth on the list of the world’s food staples
(ii) One of our favourite ways to eat potatoes is in the form of
(iii) Americans consume 2-4 billion pounds of potato chips every year and spend more than

2.3 Attempt any two of the following. Find out the words that mean the same as below:
[1 x 2 = 2]
(i) primary (paragraph 1)
(ii) eat (paragraph 2)
(iii) marinated (paragraph 5)

SECTION-B : WRITING AND GRAMMAR
(Attempt all question from this section)

Question 3.
(a) You ordered some books and stationery items from M/s. Oxford University Press, Darya Ganj, Delhi. When you checked the parcel, it contained damaged/defective items. Write a letter to the concerned firm to replace the things at their cost. Sign yourself as Sanjay/Sonia of M-3, Ashok Vihar, Bengaluru. [8]

OR

(b) You are the sales manager of Helpline communications making an inquiry on I phones X advertised in The Herald. You need 25,000 pieces for the office you have opened.

Question 4.
Write a short story, in about 200-250 words, with any one set of the cues given below. Give a suitable title to the story.
Medina woke up to loud noises downstairs and she jumped out of bed and she ran down to see what it was… [10]

OR

Jess, John and Kumar were excited to go the summer camp in Goa and they were eager with spirits high as they got piled into a bus which took them to the camp center…

Question 5.
Fill in any four of the following blanks choosing the most appropriate option from the ones given below. Write the answers in your answer -sheet against the correct blank numbers.
[1 x 4 = 4]
(a) Harish Mathur………..happy to get a new telescope as one of his birthday gifts.
(i) is
(ii) was
(iii) were
(iv) wear

(b) Harish………… gazing at the stars with his grandfather
(i) enjoying
(ii) enjoyed
(iii) enjoy
(iv) enjoys

(c) Mr.Mathur knows………… about the plantes and spaces.
(i) a lot
(ii) a lots
(iii) lots of
(iv) lot of

(d) He was a teacher for ………….. years in local schools.
(i) many
(ii) more
(iii) much
(iv) few

(e) Harish has………. serious thoughts about becoming an astronaut.
(i) has
(ii) had
(iii) have
(iv) having

Question 6.
In the following passage one word has been omitted in each line. Write the missing word, in any four sentences of the given paragraph, along with the word that comes before and the word that comes after it in the space provided. [1 x 4 = 4]

Question 7.
Rearrange any four of the following word clusters to make meaningful sentences. [1 x 4 = 4]
(a) class/ in/ our / writer/ Jasmine/ the/is/ most/ talented
(b) published/ she/ to/ be/ hopes/ a/ writer/ although
(c) Like/to/as/well/study/Jasmine/communications/would
(d) used/because/ grandmother/her/tell/to/tales/folk
(e) would/ on/ sit/ she/ grandmother’s/listen/lap/ and/ her/to/stories/great

SECTION-C : LITERATURE
(Attempt all question from this section)

Question 8.
Read the extract given below and answer the questions that follow. Write the answers in your answer sheets in one or two lines only.  [1 x 4 = 4]
(a) “Not too bad – but far too long.
The technique was fine of course
But it lacked a certain force.”
(i) Why is the frog making the above comments ?
(ii) What defects does he point out in the nightingale’s songs ?
(iii) What was the reaction of the nightingale to the above comments ?
(iv) ‘It lacked a certain force’- Why is this ironic ?

OR

(b) I’ll tell you what I’ve got to do. On Monday next I’ve got to do three things.
(i) To whom are these words spoken and by whom ?
(ii) What is the reaction of the listener to the speaker’s declaration ?
(iii) What made Abel decide on three things ?
(iv) In what manner was Abel’s decision a shock to his children ?

Question 9.
Answer any four of the following questions in 30-40 words each: [2 x 4 = 8]
(i) How did the poet come to know about the broken statue of Ozymandias ?
(ii) Why did the two boys survive only on one black bread and figs, despite making a decent earning ?
(iii) Why is Mrs. Packletide compared to ‘Nimrod’ ?
(iv) What surprising revelation is made by the ghost ? Why did the writer not believe her ?
(v) How does the poet compare ‘gilded monuments’ with ‘powerful rhyme’ ?

Question 10.
Attempt any one out of the two following long answer type questions in 100-120 words. [8]
(a) Discuss the character sketch of Mrs. Jordan and Mrs. Slater as opposed to the characters of their husbands.

OR

(b) John’s apprehensions about his wife’s reaction to her encounter with the ghost are unfounded. Justify.

Question 11.
(a) Answer the following question based on prescribed novel text for extended reading in about 200-250 words. [10]

The Diary of a Young Girl

(i) How does Anne feel about the laws that restrict the Jews’ freedom ?

OR

(ii) What role does the diary play in Anne’s life ?

(b) Answer the following question based on the prescribed novel text for extended reading in about 200-250 words.

The Story of My Life

(i) Describe Helen Keller’s stay at the Perkins Institute for the Blind in Boston.

OR

(ii) Draw a character sketch of Anne Mansfield Sullivan highlighting her monumental efforts and patience to teach a deaf and dumb girl to speak and write.

ANSWERS
SECTION-A

Answer 1.
1.1

1.  Over the centuries, people have created many rituals to accompany the consumption of their favourite drinks i.e., tea and coffee. Ex-Japanese tea ceremony, British afternoon tea etc.
2.  These drinks are popular because of their secret ingredient-caffeine.
3.  In the modem times, caffeine is delivered in the form of canned energy drinks.
4.  The dual power of caffeine to counteract physical fatigue and increase alertness is the reason why it is the world’s most popular mood-altering drug.
5.  Caffeine raises blood pressure and thus increases the risk of heart diseases. On the other hand, it helps to relieve pain, reduces asthma symptoms and increases reaction speed.
6.  A study in Ireland recommended that children and pregnant women shouldn’t consumer energy drinks.
7.  Electric lights and caffeinated food and drinks allowed people to follow a work schedule set by the clock, not by daylight or the natural sleep cycle.
8.  Without adequate sleep, the conventional eight hours out of each 24 is about right, the human body will not function at its best, physically, mentally or emotionally.
9.  The ‘Catch-22’ situation is an ironical situation as the main reason that people want caffeine is to stay awake but they can’t stay awake because they take caffaiene which doesn’t let them sleep for suggested hours.

Answer 2.
2.1 (i) Peru Inca Indian were the first to grow potatoes in 200 BC in Andes Mountains and Spanish conquistadors brought potatoes to Europe.
(ii) When Benjamin Franklin was the American ambassador to France he found potatoes made in 20 different ways and when Thomas Jefferson succeeded him he found the French fries and brought it to America.
(iii) We can say that potatoes are the favourite for Americans as they consume about 140 pounds of potatoes every year and the Europeans eat double that amount.
(iv) When a diner complained that potato chips were too thick, the attending Native American chef named George Crum cut the potatoes so thin and fried them and that’s how potato chips were born.
(v) Potato chips have become so popular that there are so many flavours across the world and 2-4 billion pounds of potato chips are consumed every year which shows that potato chips are important.

2.2. (i) Potatoes are fourth on the list of the world’s food staples-after wheat, com, and rice.
(ii) One of our favourite ways to eat potatoes is in the form of potato chips.
(iii) Americans consume 2-4 billion pounds of potato chips every year and spend more than $7 billion a year on them.

2.3. (i) first
(ii) consumer
(iii) pickled

SECTION-B

(a)
M-3, Ashok Vihar,
Bengaluru
Karnataka
10th May, 20xx
M/s. Oxford University Press,
Darya Ganj,
Delhi.

Sub.: Our Order No. 1105, dated 31st March, 2018

Dear Sir,

I had purchased some books and stationary item from you but the books sent by you are badly damaged. I think your assistant had not packed them with proper care. Some books are of old editions. They are tom and the pages are all scattered or missing.
It has become quite necessary for me to return the books. You are, therefore, requested to replace them and send the new books with great care. In the transaction, no fault lies on us. So, you are requested to bear the cost yourself.

I hope you will be careful in future and send the books at the earliest.

Yours Faithfully,
Sanjay

OR

(b)
Helpline Communication,
2nd line road, Military Line,
Tirunelveli- 5
1st August, 20 xx Sales Manager,
Tele-Communication Ltd.
25, Gurgaon- 6

Sub.: An inquiry for price of Mobile sets

Dear Sir,

Would you kindly give us a detailed information about the I phone X mobile sets recently advertised by you in “The Herald”. We are impressed by the description of the respective mobile set as advertised by you and would like to purchase if terms and conditions are found to be suitable. Our annual requirement of such set is around twenty-five thousand (25,000) pieces.
As we handle a lot of mobile sets each year, we hope and trust you will quote the most favourable prices and terms.

Yours faithfully,
M. A. Kishore Purchase Manager

Answer 4.

Fuss over nothing

Medina woke up to loud noises downstairs and she jumped out of bed and she ran down to see what it was. It was early in the morning and she came running to find out what was the commotion all about. She saw all the girls in the hostel talking aloud each discussing what made that noise. Someone said it was a box rolled over, some said it could be somebody who stalked and that got the girls spooked.
It was so typical of a girls hostel and I asked if anyone got around to check where the noise came from or if they were with the warden. But the reply was negative as they all had huddled together talking nonstop.
I took the courage to go check out though I was scared to the bones. I walked stealthily with a friend at my hand and soon found that the main door to the hostel has been left open scaring us more than ever before.
We rushed out to see who could have let the door open and we heard another scream, this time from my friend. When I turned to see what had happened, I saw an old branch from the tree fell near my friend and soon found that there was just another bigger branch that had fallen down. Now that we knew the reason for all the commotion, we all headed back to our rooms. I was unhappy that nothing more exciting happened.

OR

Fire and bear

Jess, John and Kumar were enthusiastic to go to the summer camp in Goa and they were eager and had their spirits high as got piled into a bus which took them to the camp center along with the kids from other schools. They were excited to make new friends and the bus soon started rolling. The bus was noisy with all of the children talking and laughing loud. The camp director Mr. Kishore asked us to settle down and slowly the noise died and he introduced us to the rules and safety precautions we needed to follow through the trip until we got back.
The children were paired with other members and Jess, John and Kumar looked at one another with doubtful expressions and disappointment as they thought they would be together. But anyway, they were paired with Sheila, Sheena and Rohan. They had to do a few chores together like cleaning the camp site, fetching water from the nearby river, keeping watch at night and helping in the kitchen. The kids enjoyed chores though a little grumpily as they were not used to work much at home but they were picking up.
They went trekking, long walks, taking log of the flora and fauna for their report and nights were fun as the groups got together to report their findings and experiences around the camp fire. At night John and Rohan had to keep a watch and not let the fire die. They talked for sometime and dozed a little when Rohan alerted John that there was a bear nearby. They soon got alert and saw the bear approaching them. They immediately got alert and showed their torch lights steadily at the bear’s eyes for minutes which seemed like eternity for the two and waited in patience until the bear left them, as bears do not like bright light shining at them and soon it was dawn they were ready to tell their thrilling night watch experience.

Answer 5.
(a) was
(b) enjoy
(c) a lot
(d) many
(e) had

Answer 6.

Answer 7.
(a) Jasmine is the most talented writer in our class.
(b) Although she hopes to be a published writer.
(c) Jasmine would like to study communications as well.
(d) Because her grandmother used to tell her folk tales.
(e) She would sit on her grandmother’s lap and listen to her great stories

SECTION-C

Answer 8.
(a) (i) The frog is making the above comments because he wishes to impress the nightingale as if he is an expert and let him train her.
(ii) The frog states that her songs lacked energy and were too long.
(iii) The nightingale was impressed with the comments of the frog as she was very vulnerable and innocent.
(iv) The above given line spoken by the frog is ironic because the frog has force for sure, but no finess in his voice.

OR

(b) (i) These words are spoken by Abel to his family.
(ii) The family is taken a back when they hear Abel stating that he is going to do something about the present predicament.
(iii) Abel decided on those three things due to the family’s negligence towards him.
(iv) Abel’s decision was shocking for his children because they thought in spite of being so complacent and negligent they can come back and take their father’s property.

Answer 9.
(i) The story of Ozymandias was told to the poet by a speaker who had met the traveller from an ancient land. The story of Ozymandias’ statue have been passed through generations by the word of mouth. This escalates a hint of obscurity and mystery to the statue.
(ii) Nicola and Jacopo were desperate to make as much money as possible in order to provide for the medical care of their sister Lucia, who was undergoing a treatment for T.B. They worked late at night and often waited for the last bus to sell the unsold papers because every bit mattered and that’s why they survived only on one bread and figs.
(iii) Nimrod is considered a biblical legendary hunter known for his prowess and it is clear that Mrs. Packletide is such a person who is having true penchant for the sport. The author uses the comparison to convey out her vanity and make a mockery of her.
(iv) The writer is pleasantly, surprised that all the good plots for his ghost stories have been inspired and fueled by the ghost Helen. The writer finds it very difficult to believe in the ghost as he had never seen her before. But the ghost states that she had sat on his shoulders prompting the plots for his stories.
(v) Both ‘gilded monuments’ and ‘powerful rhyme’ are used in memory of someone. The poet, however feels that his love for his friend will stand the test of time when monuments might be destroyed.

Answer 10.
(a) Both Mrs. Slater and Mrs. Jordan are clever, mean and manipulative without a tinge of empathy towards their father. They are ready to reap the benefits without doing anything for it. We see Amelia take away her father’s slippers, bureau and clock; while Elizabeth takes away her father’s watch. The ladies are not concerned about their deeds but rather have more pleasure in being presentable and showy for their father’s funeral. They are carried away by appearances and look at their father’s death as a part of drama where they need to be right in their costumes.

OR

(b) John believed that his wife was a sensitive little woman who was too scared of even a mouse. A real heart attack would happen to her if she saw a ghost in her living room. But his doubts were unfounded. Lavinia did not tremble for a moment and patiently observed and listened to Helen, the ghost. She never swooned and there was a satisfied smile on her face instead. She seemed more confident than John expects and is glad that Helen is actually helping John. John’s apprehensions about his wife’s reaction seems baseless instead he finds that there is a satisfied smile on her face.

Answer 11.
(a) (i) The Franks left Germany to live in Holland because they felt they could escape persecution. After the Germans invaded Holland in 1940, however, the same laws imposed in Germany were extended to the Netherlands. Anne thinks that the laws are unjust but she does not completely understand why the Jewish people have been singled out for this discrimination. She wishes that next time the Jews will be chosen for something good rather than something ‘ bad. Anne feels that it is unfair that the Jews cannot use streetcars, they must wear yellow stars, and must attend a particular Jewish school. Nonetheless, she is still optimistic about her family’s safety and feels relatively secure about her future. Anne accepts the restrictions as a fact of life in Amsterdam and she is thankful to the Dutch people for their sympathy, especially the ferryman, who let the Jews ride the ferry because they are not allowed to ride streetcars.

Once the SS call up for Margot, Anne realises that she is not safe from the Nazis. Her entire life and worldview is quickly transformed as she is forced into hiding. As Anne hears about more of her friends being taken to concentration camps, her fears grow and she questions why the Jews are being restricted. She also questions why she remains relatively safe while her friends outside have to suffer so much. Anne says that she does not blame the Dutch people for her family’s misfortune and her sense of perspective allows her to realise that the non-Jewish Dutch also suffer greatly during the war. When she hears that the Dutch are becoming more anti-Semitic, she is disheartened but remains optimistic about humanity.

OR

(ii) When Anne first begins writing in her diary as a thirteen-year-old girl, she feels that her friends and family all misunderstand her. Thus, she first turns to the diary as a new friend and confidant, counting on the diary to be the sympathetic, non judgmental friend she has been unable to find elsewhere. Once she goes into hiding in the Annexe, Anne feels even more misunderstood. She thinks her mother is cold and callous and feels that the other adults consider her a nuisance. The diary offers Anne much solace in the Annexe because she is in the need of companionship. Until she befriends Peter, she has no one other than her diary with whom she can openly share her fear, anger, sadness and hope. Anne calls the diary “Kitty,” indicating that she considers it a close friend. She writes to Kitty as if it was a person.

Writing conscientiously in the diary helps Anne redirect her resilient feelings instead of expressing them outrightly and causing damage to the fragile relationships within the Annexe. When everyone around her is feeling anxious and tense, Anne turns to her diary for comfort because she does not want to burden the already strained adults with her own concerns. In this way, Anne becomes very independent at a young age.

Moreover, Anne’s constant diary-writing enables her to discover her inner voice and her ability as a writer. The diary gives her the private place to explore her increasingly profound thoughts and ideas. Looking back after two years in the Annexe, Anne is able to look at the invaluable record of her experiences and analyse how she has grown and changed. In this sense, the diary becomes a substantial and a significant tool for Anne’s maturity.

(b) (i) It was Alexander Graham Bell who advised Helen’s parents to contact the Perkins Institute for Blind for her education. This was the same institute where Laura Bridgman, a deaf and a blind child had been educated and it was located in South Boston. Michael Anagnos, the director, asked the former student Anne Sullivan to become Keller’s instructor. Miss Sullivan herself was visually impaired.

Helen made friends with the little blind children. It was a unique pleasure to talk with other blind children in her own language. Until then, she had been speaking through an interpreter like a foreigner. All the eager and loving children gathered a round her and joined heartily in her frolics. They would enjoy reading the books with their fingers. They were so happy and contented that she lost all sense of pain in the pleasure of their companionship. With the blind children she felt thoroughly at home in her new environment.

Helen learnt to speak in the spring of 1890. The impulse to utter audible sounds had always been strong within her. Mrs. Lamson, who had been one of Laura Bridgeman’s teachers came to see Helen. She had taught a deaf and blind child to speak in Norway. Helen resolved that she would learn to speak. Miss Fuller offered to teach her and gave eleven lessons in all. Her first connected sentence was, “it is warm.” This was the beginning of a new journey that would take Helen places and become a source of encouragement to many across the globe.

OR

Miss Anne Mansfield Sullivan had been the singular and paramount influence on the life, character and achievements of Helen Keller. She gave a new direction, meaning and purpose to Helen’s dark life. Miss Sullivan inherited all those traits and characteristics that go into the making of a perfect teacher. She was a picture of tireless patience and unending devotion. It was her constant encouragement, help and guidance that made Helen Keller, the first deaf and blind in the world to earn a bachelor’s degree.

It was Graham Bell who advised the parents of Helen Keller to contact the Perkins Institute for the Blind. The director, Mr. Anagnos asked a former student Miss Anne Sullivan to become Keller’s instructor. Miss Sullivan was herself a visually impaired 20 years old lady. It was the beginning of a 49-year-long relationship. The relationship evolved into Miss Sullivan becoming Helen’s governess and then eventual companion. Anne Sullivan arrived at Keller’s house in March 1887. She immediately began to teach Helen to communicate by spelling words into her hand, beginning with “d-o-1-1” for the doll. It was Miss Sullivan who unfolded and developed Helen’s skills and possibilities. It was Sullivan’s genius as a teacher, her sympathy and her loving tact Which made learning so beautiful and interesting for Keller. She felt that she was inseparable from her student. All that was best in Helen Keller had been awakened by the loving touch of Miss Sullivan. Anne Sullivan stayed as a companion to Helen Keller long after she taught her. Anne Sullivan married John Macy in 1905. She remained a constant companion to Keller until she died in 1936.

We hope the CBSE Sample Papers for Class 10 English Communicative Set 4 help you. If you have any query regarding CBSE Sample Papers for Class 10 English Communicative Set 4, drop a comment below and we will get back to you at the earliest.

CBSE Sample Papers for Class 10 Science Paper 4

These Sample papers are part of CBSE Sample Papers for Class 10 Science. Here we have given CBSE Sample Papers for Class 10 Science Paper 4

Time allowed: 3 hours
Maximum marks : 80

General Instructions

• The question paper comprises two sections, A and B. You are to attempt both the sections.
• All questions are compulsory.
• All questions of Section-A and B are to be attempted separately.
• There is an internal choice in two questions of three marks each and one question of five marks.
• Question numbers 1 and 2 in Section-A are one mark question. They are to be answered in one word or in one sentence.
• Question numbers 3 to 5 in Section-A are two marks questions. These are to be answered in 30 words each.
• Question numbers 6 to 15 in Section-A are three marks questions. These are to be answered in about 50 words each.
• Question numbers 16 to 21 in Section-A are 5 mark questions. These are to be answered in 70 words each.
• Question numbers 22 to 27 in Section-B are based on practical skills. Each question is a two marks question. These are to be answered in brief.

SECTION-A

Question 1.
What is the difference in the function of trypsin and pepsin ?  [1]

Question 2.
What is regeneration and where do you see it ?  [1]

Question 3.
What is galvanisation ?  [2]

Question 4.
An object is placed at a distance of 15 cm from a convex lens of focal length 20 cm. List out the characteristics of the image formed.  [2]

Question 5.
Compare the chromosome arrangement of men and women.  [2]

Question 6.
V = \(\frac { W }{ Q } \) What does this equation tell us ? The unit of V is named after which famous
scientist ? How is potential difference measured ?  [3]

OR

The current through a 16 V tungsten filament lamp connected to a 16 V accumulator of negligible resistance is 4.0 A. Calculate:

1. The resistance of the filament,
2. The power of the lamp, and
3. The electrical energy in kWh consumed in 6 hours.

Question 7.
There are three resistors of r ohm each and a battery of E volts. How should these resistors be connected to get maximum current ? Show with a circuit diagram and find out the current drawn from the battery.  [3]

Question 8.
How does carbon manage to exist in different forms ? What are the different forms ?  [3]

Question 9.
What is water of crystallisation ? Name some elements that have these crystallisation molecules and some crystalline solids that do not contain water of crystallisation.  [3]

Question 10.
Why were objections raised to the building of dams in our country ? Which movement was Medha Patkar associated with ?  [3]

OR

What we as an individual can do to reduce our consumption of the various natural resources ?

Question 11.
What would be the consequence of a decrease in haemoglobin in our body ?  [3]

Question 12.
What is the power of accommodation of the human eye ? Why does the image distance not change even though the object distance keeps changing ?  [3]

Question 13.
pH is of great importance in our daily lives. Give three examples to prove this.  [3]

OR

A compound prepared from gypsum has the property of hardening when mixed with the right amount of water. Identify the compound and write its chemical formula. Write the chemical equation of its preparation. Mention any two uses of this compound.

Question 14.
How do Mendel’s experiments show that traits maybe dominant or recessive ?  [3]

Question 15.
What are the differences between arteries and veins ?  [3]

Question 16.
What is the role of an electric fuse in a domestic circuit ? What kind of material is used in making the fuse wire and why ?  [5]

Question 17.
Carbon compounds are poor conductors of electricity. Explain with reference to their bonding.  [5]

OR

Soaps and detergents are both types of salts. State the difference between the two. Write the mechanism of the cleansing action of soaps. Why do soaps not form lather (foam) with hard water? Mention any two problems that arise due to the use of detergents instead of soaps.

Question 18.
How we should lead our life in the present day to be more environment friendly ?  [5]

Question 19.
(a) Define optical centre of a spherical lens.  [5]
(b) A divergent lens has a focal length of 20 cm. At what distance should an object of height 4 cm from the optical centre of the lens be placed so that its image is formed 10 cm away from the lens ?
(c) Show the ray diagram for the above.

Question 20.
How did the Modem Periodic Table remove the anomalies of Mendeleev’s Periodic Table ?  [5]

Question 21.
The touch-me-not plant folds its leaves in response to touch. How does this reaction happen in the plant ?  [5]

OR

What are reflex actions ? Give examples ? Explain reflex arc by an example with labelled diagram.

SECTION-B

Question 22.
(a) An atom has an electronic configuration of 2,8,7. What is the atomic number of this element ?  [2]
(b) Can you find out the element with atomic number 17 ? What kind of bond will it form on combination with other atoms ?

Question 23.
What is a thermite reaction and where is it used ?  [2]

Question 24.
Why and how is the brain protected ?  [2]

Question 25.
When you cut open a hibiscus flower what are the major parts you see ? Draw and label them.  [2]

Question 26.
In an experiment to study the dependence of potential difference (V) on the electric current (I) across a conductor (resistor), if the circuit is on for a long time, then select two correct options from the ones given below:  [2]

1. Zero error of the ammeter will be changed.
2. Zero error of the voltmeter will be changed.
3. Value of resistance will be changed.
4. Resistor will be heated.

OR

Draw a circuit to study the dependence of current on the potential difference across a resistor.

Question 27.
An object of height 2.5 cm is placed at a distance of 15 cm from the optical centre ‘O’ of a convex lens of focal length 10 cm. Draw a ray diagram to find the position of the image formed. Mark the optical centre, ‘O’, principal focus ‘F’ and height of the image on the diagram.  [2]

ANSWERS
SECTION-A

Answer 1.
Trypsin is an enzyme found in the pancreatic juice which helps to digest proteins whereas Pepsin is an enzyme found in the stomach and it helps to digest proteins too.

Ansswer 2.
Regeneration is the ability of organisms to give rise to new individual organisms from their body parts. If an individual is cut or broken up into many pieces, these pieces can grow into separate individuals. This is seen in simple animals like Hydra and Planaria.

Ansswer 3.
Galvanisation is the process of applying a protective zinc coating to iron or steel, to prevent rusting.

Ansswer 4.
Given: u = -15 cm, ƒ= 20 cm

According to formula,

\(\frac { 1 }{ f } =\frac { 1 }{ \upsilon } -\frac { 1 }{ u } \)
\(\frac { 1 }{ 20 } =\frac { 1 }{ \upsilon } +\frac { 1 }{ 15 } \)
\(\frac { 1 }{ 20 } -\frac { 1 }{ 15 } =\frac { 1 }{ \upsilon } \)
\(-\frac { 1 }{ 60 } =\frac { 1 }{ \upsilon } \)
\(\upsilon =-60cm\)

The four characteristics of the image formed by the lens are:

• It is a virtual image.
• It is an erect image.
• It is an enlarged image.
• It is at a distance of 60 cm on the same side of the lens as the object.

Ansswer 5.
Human beings have 23 pairs of chromosomes. One chromosome of each pair is maternal and one is paternal. Of the 23 pairs, 22 pairs are called perfect pairs. One pair called the sex chromosomes are different. In women there are two X chromosomes while in men there is one X and one Y chromosome. So women are XX and men are XY.

Ansswer 6.
The given equation tells us the relationship between potential difference, charge, and work done to move the charge. The equation shows that the electric potential difference between two points in , an electric circuit carrying some current is the work done to move a unit charge from one point to another. The unit of V is named after Alessandro Volta, an Italian physicist. The S.I. unit of potential difference is volt.

OR

Given: V = 16 volt, I = 4.0 ampere, t = 6 hours

• Resistance, R = V/I = \(\frac { 16 }{ 4 } \) = 4Ω
• Power,P = V x I = 16 x 4 = 64W
• Electrical energy, W = VIt = 16 x 4 x 6 = 384 Wh = 0.384 kWh

Ansswer 7.
These resistors should be connected in parallel with the battery to get maximum current.

Let the equivalent resistance be R Ω.

\(\frac { 1 }{ R } =\frac { 1 }{ r } +\frac { 1 }{ r } +\frac { 1 }{ r } \)
\(\frac { 1 }{ R } =\frac { 1+1+1 }{ r } =\frac { 3 }{ r }\)
\(R=\frac { r }{ 3 } \)
V=I × R

According to ohm’s law,

Current(I) = E × \(\frac { 3 }{ r } =\frac { 3E }{ r } \)

Answer 8.
The process by which carbon exists in different forms is called allotropy. The different compounds have the same chemical properties but very different physical properties. Diamond and graphite are the two allotropic forms of carbon. There is a difference in the properties because of a difference in which the carbon atoms are bonded to one another. In diamond, each carbon atom is bonded to four other carbon atoms forming a rigid three-dimensional structure. In graphite, each carbon atom is bonded to three other carbon atoms in the same plane giving a hexagonal array. One of these is a double bond and thus the valency of carbon is satisfied.

Answer 9.
Water of crystallisation is the fixed number of water molecules present in one formula unit of a salt. When we heat the crystals, this water is removed and the salt turns white. 1 formula unit of CuSO₄ has 5 water molecules so it is written as CuSO₄.5H₂O. Gypsum is another salt which has water of crystallisation. It has 2 water molecules. It has the formula CaSO₄.2H₂O. The crystalline solids which do not contain water of crystallisation are NaCl, KNO₃, C₁₂H₂₂O₁₁ and KMnO₄.

Answer 10.
Dams are built to generate hydroelectric power. Water is stored in huge dams built at great heights. Since the water in the reservoir would be refilled every time it rains hydroelectric power is a renew-able source of energy. However, there are some problems associated with the construction of dams. Large areas of agricultural land and human habitation has to be sacrificed. Large ecosystems could be destroyed while submerged and rotting vegetation could give rise to greenhouse gases. Suitable and satisfactory rehabilitation of the displaced people has to be ensured. Medha Phatkar is a famous social activist and she was associated with the “Narmada Bachao Andolan” against the construction of the Sardar Sarovar project on river Narmada.

OR

As an individual we can follow the principle of reduce, recycle and reuse (3Rs strategy) to reduce our consumption of the various natural resources.

1. Reduce: We can reduce our consumption of various resources like electricity consumption by switching off unnecessary lights and fans.We can save water by immediately repairing faulty taps and should ensure there is no unnecessary wastage of water. We should not waste food and can prepare only as much as required.
2. Recycle : We must clearly segregate recyclable wastes like plastic, paper, metal and glass and use them to make something fresh instead of preparing something new.
3. Reuse: In this process, we need to find alternative uses for the things that we once considered waste. Used bottles or containers can be used to store various things at home. One side papers can be used for writing on the other side as a scribbling pad. Recycling of used things greatly reduces waste generation.
   Finally we must manage our natural resources in such a way that they shall last for the future generations and are not exploited for short time gains.

Answer 11.
A decrease in the amount of haemoglobin in our body means anaemia and a general weakness of the body. Haemoglobin is the oxygen carrying pigment of the blood. In its absence very little oxygen would be transported which means all the cells will not receive their supply of oxygen. In the absence of oxygen, food will not be oxidised and there will be no release of energy. This in turn affects the body’s ability to do work.

Answer 12.
The ability of the eye lens to adjust its focal length is called power of accommodation of the human eye.
The focal length of the human eye lens can change i.e., increase or decrease depending on the distance of the object from the eye and because of this the image distance does not change. As the distance of the object from the eye varies, the ciliary muscles modify the curvature of the lens to change its focal length.

Answer 13.
pH is important in our daily lives. It plays a role in our digestive system, self-defence of animals and
plants and in tooth decay.

1. Digestive system: Our stomach produces hydrochloric acid to help in digestion of food. Some¬times during indigestion or when a person is hungry for long too much of acid is produced and this causes pain and irritation. To neutralise this, the patient is given antacids which contains a mild base.
2. Self-defence of animals and plants : Sometimes when we are stung by a honey-bee or ants it causes pain, swelling and irritation. This is due to an acid produced at the site of the sting. For relief, baking soda is used as it contains a mild base.
3. Tooth decay: Tooth decay is caused by bacteria which produce acids using the left-over food in our mouth. This can be avoided by cleaning the mouth regularly after eating. Toothpastes are slightly basic and they neutralise the excess acid in the mouth and prevent tooth decay.

OR

Gypsum is a salt which has water of crystallisation. It has 2 water molecules as water of crystallisation. When it is heated it loses the water molecules and becomes calcium sulphate hemihydrate (CaSO₄.1/2H₂O) this is called Plaster of Paris. It is a white powder and when mixed with water it changes again to gypsum which is a hard solid mass.

Uses of Plaster of Paris:

• It is used as plaster for supporting fractured bones in the right position.
• It is used for making toys, materials for decoration and for making smooth surfaces.

Answer 14.
Mendel performed his experiments using contrasting characters of pea plants. He crossed a tall plant (TT) and a dwarf plant (tt). In the F₁ generation he found all plants to be tall. Now Mendel wanted to see if all the tall plants of F1 generation were like the tall parents. So he self-pollinated the F1 tall plants. In F2, he found 3/4^th plants were tall and rest l/4^th were dwarf. This clearly shows that though both the tall and dwarf characters were inherited in F1, only tallness trait expressed itself. This means both TT and Tt are tall plants while tt is a dwarf plant. Hence, a single copy of T is enough to express tallness while 2 copies of t are required to express dwarfness. Moreover Tt did not express any in between character. Thus Mendel’s experiments clearly show that traits could either be dominant or recessive.

Answer 15.

Answer 16.
The electric fuse plays an important role in the domestic circuit. It is a safety device which is used to limit the current in an electric circuit. The use of a fuse safeguards the circuit and the appliances connected in that circuit from being damaged. The fuse is always connected in series with the device. A fuse is a short piece of wire of uniform area of cross-section and high resistance, made up of a material of low melting point, so that it may easily melt due to overheating when current in excess to the prescribed limit passes through it. Generally an alloy of lead and tin is used as the material of the fuse wire because its melting point is low and resistivity is more than that of copper, aluminium, etc.

The main fuse in domestic wiring is encased in a cartridge of porcelain of similar material with metal ends. The fuses for domestic purposes are rated as 1 A, 2 A, 3 A, 5 A, 10 A etc.

Answer 17.
Carbon compounds are poor conductors of electricity. Carbon has a valency of 4. To attain the stable configuration of noble gases, carbon atom needs to either gain or lose 4 electrons.

1. If it were to gain 4 electrons it would become C^4- anion, but this makes it difficult to hold onto the 10 electrons.
2. If it were to lose 4 electrons it would become C⁴⁺ cation, but this means a lot of energy would be required to pull out the 4 electrons and leave the carbon atom with 6 protons and 2 electrons. The easy way out is to share the 4 electrons with atoms of either carbon or other elements. The shared pair is then common to both the atoms. This bond formed by a sharing of electrons is called as covalent bond and such compounds are known as covalent compounds. As there are no charged particles available covalent compounds are poor conductors of electricity. They have low melting and boiling points too.

OR

Mechanism of the cleansing action of soaps : The dirt present on clothes is organic matter and insoluble in water. Therefore, it cannot be removed by only washing with water. When soap is dissolved in water, its hydrophobic ends attach themselves to the dirt and removes it from the cloth. Then, the molecules of soap arranges themselves in micelles form and traps the dirt at the centre of the cluster. These micelles remain suspended in the water. Hence, the dust particles are easily rinsed away by water.

Soaps do not form lather with hard water : Soap is a sodium or potassium salt of long chain fatty acids. Hard water contains salts of calcium and magnesium. When soap is added to hard water, calcium and magnesium ions present in water displaces sodium or potassium ion present in soap forming insoluble substance called scum. A lot of soap is wasted in this process.
Problems that arise due to the use of detergents instead of soap:

• Detergents being non-biodegradable, they accumulate in the environment causing pollution. In soil, the presence of detergents leads to pH changes making soil infertile.
• The entry of detergents into food chain leads to bioaccumulation in living beings and tends towards serious health issues.

Answer 18.
To be more environment-friendly in the present day we should make the following changes in our life-style.

1. We should use the public transport system instead of personal vehicle for commuting.
2. We should look to use non-conventional sources of energy wherever feasible.
3. We should strictly follow the policy of Reduce, Reuse and Recyle.
4. We should avoid wastage of resources in our day to day lives such as water, electricity and cooking gas.
5. While adopting a modem life style we must look at sustainable development and reduced generation of waste.
6. Let us adopt back to nature techniques wherever possible. Let us use well ventilated rooms instead of air-conditioners. Let us have a roof garden to keep our homes cool naturally.

Answer 19.
(a) Optical centre is a point on the principal axis of the lens such that a ray of light passing through it emerges parallel to its direction of incidence.
(b) Given :ƒ= – 20 cm, h_o = 4 cm and υ = -10 cm

\(\frac { 1 }{ f } =\frac { 1 }{ \upsilon } -\frac { 1 }{ u } \)
\(\frac { -1 }{ 20 } =-\frac { 1 }{ 10 } -\frac { 1 }{ u } \)
\(\frac { 1 }{ u } =-\frac { 1 }{ 10 } +\frac { 1 }{ 20 } \)
\(\frac { 1 }{ u } =\frac { -2+1 }{ 20 } =\frac { -1 }{ 20 } \)
u = 20 cm
\(m=\frac { { h }_{ i } }{ { h }_{ 0 } } =\frac { \upsilon }{ u } \)
\(\frac { { h }_{ i } }{ 4 } =\frac { -10 }{ -20 } \)
2h_i = 4
h_i = 2 cm

(c)

Answer 20.
In 1913, Henry Moseley showed that the atomic number of an element is a more fundamental property than its atomic mass. So Mendeleev’s Periodic law was modified and the atomic number was adopted as the basis of the Modern Periodic Table. Prediction of properties of elements could be made more accurately when elements are arranged on the basis of increasing atomic number. The Modem Periodic Law states that, ” properties of elements are a periodic function of their atomic numbers”.

The Modem Periodic table has 18 vertical columns called groups and 7 horizontal rows called periods. The position of an element in the Periodic Table tells us about its chemical reactivity. The valence electrons determine the kind and number of bonds formed by an element. The metallic character decreases across a period while it increases down a group. While metals occur on the left of the periodic table non-metals occur on the right side of the periodic table. In the centre there is space for the metalloids.

Answer 21.
The touch-me-not plant folds its leaves as soon as it is touched. The plant moves its leaves in response to touch. If we think about where exactly the plant is touched, and what part of the plant actually moves it is obvious that the movement happens at a point different from the point of touch. Here movement has happened at points far away from the point where it was touched. Thus information about the touch has been communicated. The plant uses electrical-chemical means to convey information from cell to cell but unlike animals there is no specialised tissue in plants for the conduction of information. Plant cells change shape by changing the amount of water in them resulting in swelling and shrinking of the leaves.

OR

Reflex action is a quick, automatic, involuntary, unconscious response in the body brought about by a stimulus. Examples of reflex action:

• Withdrawal of hand suddenly on touching a hot plate.
• Withdrawal of finger suddenly when pricked by a thorn.
• Shivering of our body on feeling cold.
• Sudden closure of our eyelids when bright light falls on our eye.

Reflex arc: It is the shortest route taken by impulse from receptor to effector.
Example: When we touch a hot plate by our finger, we instantly withdraw our hand. Here stimulus is touching a hot plate, receptors are our fingers. The specialized epithelial cells of our fingers respond to stimulus and convert into impulse. This impulse is carried by sensory neuron to spinal cord which generates a motor impulse. This impulse is carried by motor neuron to effector organ i.e., muscles of hand. Response is withdrawal of our hand.

SECTION-B

Answer 22.
(a) The electronic configuration is 2,8,7 means the atomic number is 2+ 8+ 7,
which is equal to 17.
(b) The element with atomic number 17 is chlorine (Cl). With a valency of 7 it tends to gain an electron from another combining atom so that it can get the stable octet configuration. On gaining an electron it becomes electronegative ion or anion. So it forms electrovalent or ionic bonds with other atoms.

Answer 23.
Thermite reaction is a reaction between a metal and a non-metal. During this reaction a large amount of heat is produced which changes the metal into a molten state. The reaction of aluminium with ferric oxide is a thermite reaction. It is used for welding or joining railway tracks or cracked machine parts.

Fe₂0₃ + 2Al → 2Fe + Al₂0₃ + Heat

Answer 24.
The brain is the main coordinating centre of the body. The brain and the spinal cord make up the central nervous system. The brain is a delicate organ and needs to be carefully protected. It lies inside a bony box called cranium. Further inside the cranium and around the brain there are 3 layers filled with the cerebro-spinal fluid which act as shock absorbers.

Answer 25.
On opening a section of the hibiscus flower we can see the green sepal first, then the colourful petals and next the slender stamens. The stamen or the male reproductive part consists of the anther and filament. In the centre we can see the female reproductive part called carpel. It consists of 3 parts, stigma, style and the ovary at the bottom.

Answer 26.
(c) Value of resistance will be changed.
(d) Resistor will be heated.

Answer 27.
The required ray diagram, is drawn as follows:

Given: u = -15 cm, h₀ = 2.5 cm, ƒ = 10 cm
We Know that

\(\frac { 1 }{ f } =\frac { 1 }{ \upsilon } -\frac { 1 }{ u } \)
\(\frac { 1 }{ 10 } =\frac { 1 }{ \upsilon } -\frac { 1 }{ (-15) } \)
\(\frac { 1 }{ \upsilon } =\frac { 1 }{ 10 } -\frac { 1 }{ 15 } =\frac { 1 }{ 30 }\)
Image distance, υ = 30 cm
\(\frac { { h }_{ i } }{ { h }_{ 0 } } =\frac { \upsilon }{ u } \)
\(\frac { { h }_{ i } }{ 2.5 } =\frac { 30 }{ -15 } \)
h_i = -5 cm

Therefore, a real, inverted and magnified image of size 5 cm is formed at a distance of 30 cm from the lens.

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CBSE Sample Papers for Class 10 Hindi A Set 1

These Sample Papers are part of CBSE Sample Papers for Class 10 Hindi A. Here we have given CBSE Sample Papers for Class 10 Hindi A Set 1

निर्धारित समय : 3 घण्टे
अधिकतम अंक : 80

सामान्य निर्देश

* इस प्रश्न-पत्र में चार खण्ड हैं
खण्ड (क) : अपठित अंश -15 अंक
खण्ड (ख) : व्यावहारिक व्याकरण -15 अंक
खण्ड (ग) : पाठ्य पुस्तक एवं पूरक पाठ्य पुस्तक -30 अंक
खण्ड (घ) : लेखन -20 अंक
* चारों खण्डों के प्रश्नों के उत्तर देना अनिवार्य है।
* यथासंभव प्रत्येक खण्ड के प्रश्नों के उत्तर क्रमश: दीजिए।

खण्ड (क) : अपठित अंश

प्र. 1. निम्नलिखित गद्यांश को ध्यानपूर्वक पढ़िए और नीचे लिखे प्रश्नों के उत्तर लिखिए [8]
तिलक ने हमें स्वराज का सपना दिया और गाँधीजी ने उस सपने को दलितों और स्त्रियों से जोड़कर एक ठोस सामाजिक अवधारणा के रूप में देश के सामने रखा। स्वतन्त्रता के उपरान्त बड़े-बड़े कारखाने खोले गए, वैज्ञानिक विकास भी हुआ, बड़ी-बड़ी योजनाएँ भी बनीं, किन्तु गाँधीवादी मूल्यों के प्रति हमारी प्रतिबद्धता सीमित होती चली गई। दुर्भाग्य से गाँधी के बाद गाँधीवाद का कोई ऐसा व्याख्याकार न मिला जो राजनैतिक, सामाजिक और आर्थिक सन्दर्भो में गाँधीजी की सोच की समसामयिक व्याख्या करता। इस कारण यह विचार लोगों में घर करता चला गया कि गाँधीवादी विकास का मॉडल धीमे चलने वाला और तकनीकी प्रगति से विमुख है। उस पर ध्यान देने से हम आधुनिक वैज्ञानिक युग की दौड़ में पिछड़ जायेंगे। यह कहना गलत नहीं होगा कि कुछ लोगों की पाखंडी जीवन शैली ने भी इस धारणा को और पुष्ट किया है। इसका परिणाम यह हुआ कि देश में बुनियादी तकनीकी और औद्योगिक प्रगति तो आई पर देश के सामाजिक और वैचारिक ढाँचे में जरूरी बदलाव नहीं लाए गए। अत: तकनीकी विकास ने समाज में व्याप्त व्यापक फटेहाली, धार्मिक कूपमंडूकता और जातिवाद को नहीं मिटाया।
(i) तिलक का सपना क्या था तथा गाँधीजी ने उसका क्या किया? [2]
(ii) स्वतन्त्रता के बाद देश में क्या हुआ तथा गाँधीवाद के प्रति लोगों की क्या दृष्टि रही? [2]
(iii) लोगों के मन में क्या विचार घर कर गया और क्यों ? [2]
(iv) देश के सामाजिक और वैचारिक ढाँचे में बदलाव न आने का क्या कारण था? [1]
(v) औद्योगिक’ शब्द से संज्ञा शब्द बनाइए। [1]

प्र. 2. निम्नलिखित काव्यांश को ध्यानपूर्वक पढ़कर पूछे गये प्रश्नों के उत्तर दीजिए [7]
जिस पर गिरकर उदर-दरी से तुमने जन्म लिया है,
जिसका खाकर अन्न, सुधा-सम नीर-समीर पिया है,
वह स्नेह की मूर्ति दयामयी माता-तुल्य मही है,
उसके प्रति कर्त्तव्य तुम्हारा क्या कुछ शेष नहीं है,
पैदा कर जिस देश-जाति ने तुमको पाला-पोसा
किए हुए है वह निज हित का तुमसे बड़ा भरोसा
उससे होना उऋण प्रथम है सत्कर्त्तव्य तुम्हारा,
फिर दे सकते हो वसुधा को शेष स्वजीवन सारा।
(i) पृथ्वी किसके समान है और क्यों ? [2]
(ii) व्यक्ति को देश के प्रति अपना जीवन क्यों अर्पित करना चाहिए? [2]
(iii) कवि ने मातृभूमि के प्रति किस कर्तव्य का स्मरण कराया है? [1]
(iv) मनुष्य का सत्कर्त्तव्य क्या है? [1]
(v) कविता में प्रयुक्त हुए पृथ्वी के दो पर्यायवाची लिखिए। [1]

खण्ड (ख) : व्यावहारिक व्याकरण

प्र. 3. निर्देशानुसार उत्तर दीजिए [3]
(क) वह बाजार गया और फल खरीदे। (मिश्र वाक्य बनाइए।)
(ख) वह गाड़ी में बैठकर घर चला गया। (संयुक्त वाक्य बनाइए।)
(ग) मैं पहले खाना खाऊँगा फिर विद्यालय जाऊँगा। (सरल वाक्य बनाइए)

प्र. 4. निर्देशानुसार उत्तर दीजिए [4]
(क) लड़कियों ने स्टेज पर नृत्य किया। (कर्मवाच्य में बदलिए)
(ख) मेरे द्वारा निबन्ध लिखा गया। (कर्तृवाच्य में बदलिए)
ग) वह नहीं चलती। (भाववाच्य में बदलिए)
(घ) सुरेश ने झूठ बोला। (कर्मवाच्य में बदलिए)

प्र. 5. रेखांकित पदों का पद परिचय लिखिए [4]
(क) उसकी आँख में कुछ गिर गया है।
(ख) विद्वान व्यक्ति सर्वत्र पूजा जाता है।
(ग) मैं सवेरे उठता हूँ।
(घ) रमेश ने अपने भाई के लिए पुस्तक खरीदी।

प्र. 6. निम्नलिखित प्रश्नों के उत्तर निर्देशानुसार लिखिए [4]
(क) शृंगार रस का स्थायी भाव लिखिए।
(ख) निर्वेद में कौन-सा रस निष्पन्न होता है।
(ग) रे नृप बालक ! कालबस बोलत तोहि ने सँभार।
धनुही सम त्रिपुरारि धनु विदित सकल संसार ।।
-उपरोक्त पंक्ति में कौन-सा रस है?
(घ) शृंगार रस के कितने भेद होते हैं नाम लिखिए।

खण्ड (ग) : पाठ्य पुस्तक एवं पूरक पाठ्य पुस्तक

प्र. 7. निम्नलिखित गद्यांश को ध्यानपूर्वक पढ़कर नीचे दिए गए प्रश्नों के उत्तर लिखिए [5]
कस्बा ब्रहुत बड़ा नहीं था। जिसे पक्का मकान कहा जा सके वैसे कुछ ही मकान और जिसे बाजार कहा जा सके वैसा ही एक बाजार था। कस्बे में एक लड़कों का स्कूल, एक लड़कियों का स्कूल, एक सीमेंट का छोटा-सा कारखाना, दो ओपन एयर सिनेमाघर और एक नगरपालिका भी थी । नगरपालिका थी तो कुछ-न-कुछ करती भी रहती थी। कभी कोई सड़क पक्की करवा दी, कभी पेशाबघर बना दिए, कभी कबूतरों की छतरी बनवा दी तो कभी कवि सम्मेलन करवा दिया। इसी नगरपालिका के किसी उत्साही बोर्ड या प्रशासनिक अधिकारी ने एक बार ‘शहर’ के मुख्य बाजार के मुख्य चौराहे पर नेताजी सुभाष चंद्र बोस की एक संगमरमर की प्रतिमा लगवा दी।
(क) हालदार साहब को उस कस्बे से कब और क्यों गुजरना पड़ा था? [2]
(ख) कस्बा कैसा था? उसकी क्या विशेषताएँ थीं ? [2]
(ग) कस्बे की नगरपालिका क्या-क्या कार्य करती थी? [1]

प्र. 8. निम्नलिखित प्रश्नों के उत्तर संक्षेप में लिखिए [2×4=8]
(क) लेखिका के व्यक्तित्व का सही विकास कब हुआ? [2]
(ख) ‘एक कहानी यह भी’ के आधार पर बताइए। बिस्मिल्ला खाँ को संगीत की आरम्भिक प्रेरणा किससे मिली ? [2]
(ग) लेखिका के अपने पिता से वैचारिक मतभेदों को अपने शब्दों में लिखिए। [2]
(घ) अपनों का विश्वासघात मनुष्य पर क्या प्रभाव डालता है? ‘एक कहानी यह भी’ के आधार पर लिखिए। [2]

प्र. 9. निम्नलिखित काव्यांश को ध्यानपूर्वक पढ़कर नीचे दिए गए प्रश्नों के उत्तर लिखिए [5]
यश है या न वैभव है मान है न सरमाया,
जितना ही दौड़ा तू उतना ही भरमाया,
प्रभुता का शरण-बिंब केवल मृगतृष्णा है,
हर चन्द्रिका में छिपी एक रात कृष्णा है।
जो है यथार्थ कठिन उसका तू कर पूजन ।
छाया मत छूना ।
मन, होगा दुख दूना।
(क) कवि ने यश, वैभव, मान आदि को किसके समान बताया है? [2]
(ख) ‘हर चंद्रिका में छिपी एक रात कृष्णा है’-इस पंक्ति के माध्यम से कवि किस तथ्य को बताना चाहता है? [2]
(ग) व्यक्ति को कठिन यथार्थ का पूजन क्यों करना चाहिए? [1]

प्र. 10. निम्नलिखित प्रश्नों के उत्तर संक्षेप में लिखिए [2×4=8]
(क) परशुराम ने धनुष तोड़ने वाले के विषय में पूछा तो श्रीराम ने धनुष मेरे द्वारा टूट गया है, सीधा उत्तर न देकर ऐसा क्यों कहा कि “धनुष तोड़ने वाला आपका कोई दास होगा”। [2]
(ख) माँ ने बेटी को क्या-क्या सीख दी? ‘कन्यादान’ कविता के आधार पर बताइए। [2]
(ग) “संगतकार’ कविता में कवि क्या संदेश देना चाहता है? [2]
(घ) लक्ष्मण ने अपने कुल की क्या परम्परा बताई ? [2]

प्र. 11. ‘कटाओ’ में किसी भी दुकान का न होना उसके लिए वरदान है।” इस कथन के पक्ष में अपनी राय दीजिए।

अथवा

प्रकृति ने जल संचय की व्यवस्था किस प्रकार की है? [4]

खण्ड (घ) : लेखन

प्र. 12. निम्नलिखित में से किसी एक विषय पर दिए गए संकेत बिन्दुओं के आधार पर लगभग 200 से 250 शब्दों में निबंध लिखिए। [10]
(क) इंटरनेट का प्रभाव

• इंटरनेट : अनुपम सुविधा
• उपयोगिता की दिशाएँ
• दुरुपयोग के बिन्दु
• समाधान व संदेश

(ख) ग्लोबल वार्मिंग के खतरे

• अर्थ
• कारण व समस्याएँ
• बचाव के उपाय
• समाधान व संदेश

(ग) स्वच्छ भारत : एक कदम स्वच्छता की ओर

• स्वच्छता का महत्त्व
• वर्तमान समय में भारत में स्वच्छता की स्थिति
• स्वच्छ भारत अभियान का लक्ष्य
• उपसंहार

प्र. 13. अपने नगर में बढ़ते अवैद्य निर्माण की समस्या की ओर प्रशासन का ध्यान आकृष्ट करने के लिए किसी समाचार-पत्र के संपादक के नाम पत्र लिखिये। [5]

अथवा

आपके क्षेत्र में डाक विभाग की अव्यवस्था की शिकायत करते हुए पोस्टमास्टर जी को पत्र लिखिए।

प्र. 14. किसी नहाने के साबुन का विज्ञापन तैयार कीजिए। उसकी विशेषताएँ बताते हुए 25-50 शब्दों में एक विज्ञापन तैयार कीजिए। [5]

अथवा

विद्यालय की कार्यानुभव-प्रयोगशाला में बनी मोमबत्तियाँ तथा अन्य उपयोगी वस्तुओं की बिक्री हेतु लगभग 25 शब्दों में एक विज्ञापन लिखिए।

उत्तरमाला

खण्ड (क)

उत्तर 1. (i) तिलक ने स्वराज का सपना दिया था और गाँधीजी ने उस स्वप्न को दलितों और स्त्रियों से जोड़कर एक ठोस सामाजिक अवधारणा के रूप में देश के सामने रखा।
(ii) स्वतन्त्रता के बाद देश में बड़े-बड़े कारखाने खोले गए वैज्ञानिक विकास भी हुआ, बड़ी-बड़ी योजनाएँ बनीं, किन्तु गाँधीवादी मूल्यों के प्रति हमारी प्रतिबद्धता सीमित होती चली गई।
(iii) लोगों के मन में यह विचार घर कर गया कि गाँधीवादी विकास का मॉडल धीमे चलने वाला तथा तकनीकी प्रगति से विमुख है। क्योंकि गाँधीजी के बाद कोई ऐसा व्याख्याकार नहीं मिला जो सामाजिक, राजनैतिक और आर्थिक रूप में गाँधीजी के विचारों की व्याख्या करता।
(iv) लोगों में गाँधीवादी मूल्यों के प्रति लगाव का अभाव इसका मुख्य कारण था।
(v) औद्योगिक शब्द का संज्ञा शब्द है ‘उद्योग’।।

उत्तर 2. (i) पृथ्वी को स्नेह की मूर्ति, दयामयी माँ के समान बताया है क्योंकि माँ के गर्भ से जन्म लेने के बाद व्यक्ति का पालन-पोषण इसी पृथ्वी पर होता है।
(ii) क्योंकि जन्म लेने के बाद व्यक्ति का पालन-पोषण देश, समाज और जाति के लोगों के बीच होता है। अंततः वह अपने जीवन को समर्पित करके देश का ऋण चुका सकता है।
(iii) कवि ने मातृभूमि के प्रति अपने दायित्वों के निर्वाह का स्मरण कराया है।
(iv) मातृभूमि ने हमें जो कुछ प्रदान किया है उसका ऋण चुकाना ही सत्कर्तव्य है।
(v) पृथ्वी-मही, वसुधा।

खण्ड (ख)

उत्तर 3. (क) उसे फल खरीदने थे इसलिए बाजार गया।
(ख) वह गाड़ी में बैठा और घर चला गया।
(ग) मैं खाना खाकर विद्यालय जाऊँगा।

उत्तर 4. (क) लड़कियों द्वारा स्टेज पर नृत्य किया गया।
(ख) मैंने निबन्ध लिखा।
(ग) उससे नहीं चला जाता।
(घ) सुरेश द्वारा झूठ बोला गया।

उत्तर 5. (क) उसकी-सर्वनाम, संबंधवाचक, पुल्लिंग, एकवचन।
(ख) विद्वान-विशेषण, गुणवाचक, पुल्लिंग, एकवचन।
(ग) उठता हूँ-अकर्मक क्रिया, पुल्लिंग, एकवचन, उत्तम पुरुष।।
(घ) भाई (के लिए)-जातिवाचक संज्ञा, पुल्लिंग, एकवचन संप्रदान कारक अप्रत्यक्ष कर्म का प्रकार्य ।

उत्तर 6. (क) शृंगार रस का स्थायी भाव है प्रेम या रति ।
(ख) निर्वेद में शांत रस निष्पन्न होता है।
(ग) इन पंक्तियों में रौद्र रस है।
(घ) श्रृंगार रस के दो भेद होते हैं-संयोग शृंगार और वियोग श्रृंगार।

खण्ड (ग)

उत्तर 7. (क) हालदार साहब को हर पंद्रहवें दिन कम्पनी के काम से उस कस्बे से गुजरना पड़ता था।
(ख) कस्बा बहुत बड़ा नहीं था। वहाँ कुछ पक्के मकान और एक बाजार था। लड़कों का एक स्कूल और लड़कियों का एक स्कूल था, सीमेंट का एक छोटा कारखाना, दो ओपन एयर सिनेमाघर और एक नगरपालिका थी।
(ग) कस्बे में नगरपालिका कभी कोई सड़क बनवा देती थी, कभी और पेशाबघर बना दिए, कभी कबूतरों की छतरी बनवा दी, कभी
कवि सम्मेलन करवा दिया।

उत्तर 8. (क) जब लेखिका की बड़ी बहन की शादी हो गई तथा बड़े भाई पढ़ाई के लिए कोलकाता चले गए तब उनके व्यक्तित्व का विकास होना शुरू हो गया। तब पिताजी ने भी उन पर ध्यान देना शुरू किया।
(ख) बिस्मिल्ला खाँ ने संगीत की वर्णमाला का पहला अक्षर रसूलन बाई और बतूलन बाई नाम की गायिका बहनों के गीतों को सुनकर सीखा।
(ग) लेखिका के पिता गोरे रंग को पसन्द करते थे जबकि लेखिको काली थी। अपने पिता का शक्की स्वभाव लेखिका को पसन्द नहीं था। लेखिका ने अपने पिता की मर्जी के खिलाफ विवाह किया था। पिता को उसका लड़कों के साथ सड़क पर घूमना, नारेबाजी करना व हड़ताल करवाना पसन्द नहीं था।
(घ) अपनों का विश्वासघात मनुष्य को तोड़कर रख देता है। इससे मनुष्य बहुत शक्की, अहंकारी, क्रोधी और चिड़चिड़ा हो जाता है। उसका व्यक्तित्व खंडित हो जाता है।

उत्तर 9. (क) कवि ने यश वैभव, मान आदि को भ्रमित करने वाली मृगतृष्णा के समान बताया है क्योंकि मनुष्य यश आदि के लिए भ्रमित होता है कभी तृप्त नहीं होता।
(ख) मानव जीवन में सुख के बाद दुख की काली छाया भी सामने खड़ी रहती है। यहाँ चाँदनी रात मनुष्य के सुख का प्रतीक है तो काली रात दुख का प्रतीक है।
(ग) मनुष्य को यथार्थ से न भागकर उसका सामना करना चाहिए। जीवन में कठिनाइयाँ आती हैं, इनसे विचलित हुए बिना उनको । सामना करना चाहिए।

उत्तर 10. (क) श्रीराम परशुराम के क्रोधित स्वभाव से परिचित थे और स्वयं विनम्रता के धनी थे तथा वे यह भी जानते थे कि विनम्रता से क्रोध को शान्त किया जा सकता है इसीलिए उन्होंने स्वयं को परशुराम का दास (अनुचर) बताते हुए कहा कि धनुष तोड़ने वाली आपका ही कोई दास होगा।
(ख) माँ ने बेटी को सीख देते हुए कहा कि पानी में झाँककर अपने सौन्दर्य पर घमंड न करना, वस्त्र और आभूषण को बंधन मत बनने देना। अपनी मर्यादाओं का पालन करना।
(ग) संगतकार कविता में कवि यह संदेश देना चाहता है कि हमें बड़े कलाकारों, मुख्य गायक-गायिकाओं की सहायता करने वाले उन व्यक्तियों को भी उचित सम्मान देना चाहिए, जो गुमनामी में रहकर बड़े कलाकारों या गायक-गायिकाओं की सफलता में महत्वपूर्ण भूमिका निभाते हैं।
(घ) लक्ष्मण ने अपने कुल की यह परंपरा बताई है कि हमारे यहाँ देवता, ब्राह्मण, ईश्वरभक्त तथा माँ पर शूरवीरता नहीं दिखाई जाती क्योंकि इन्हें मारने से पाप लगता है और इनसे हारने से बदनामी होती है।

उत्तर 11. कटाओ सिक्किम की एक खूबसूरत किन्तु अनजान सी जगह है। यह अपनी स्वच्छता और सुन्दरता के कारण हिन्दुस्तान का स्विटजरलैंड कहलाता है। यहाँ किसी भी प्रकार चीजें किराये पर मुहैया करवाने वाली दुकानों की कतारें या एक भी दुकान न थी। यहाँ का व्यवसायीकरण नहीं हुआ। यदि वहाँ दुकानों की कतार होती तो स्थानीय आबादी भी बढ़ेगी और पर्यटकों की भीड़ भी। अंतत: वहाँ भी प्रदूषण अपने पाँव पसारेगा। ऐसे में कटाओ में दुकानों का न होना एक वरदान ही है।

अथवा

“साना-साना हाथ जोड़ि…..” पाठ में यह स्पष्ट किया गया है कि कटाओ के हिम शिखर पूरे एशिया के जलस्तम्भ हैं। प्रकृति बड़े नायाब ढंग से सर्दियों में बर्फ के रूप में जल संग्रह कर लेती है और गर्मियों में जब पानी के लिये त्राहि-त्राहि मचती है, तो ये ही बर्फ शिलाएँ पिघल-पिघलकर जलधारा बनकर हमारी प्यास बुझाती हैं। इस प्रकार प्रकृति ने बड़े अद्भुत ढंग से जल संचय की व्यवस्था की है।

खण्ड (घ)

उत्तर 12. (क) इंटरनेट का प्रभाव
इंटरनेट अनुपम सुविधा-इंटरनेट के माध्यम से इंसान के काम करने के तरीके में क्रान्तिकारी परिवर्तन आया है। इसके कारण मनुष्य के समय और मेहनत की बहुत बचत हुई है। ये कम समय में पूरी जानकारी को आप तक पहुँचाने की दक्षता रखता है। आज इसका प्रभाव दुनिया के हर कोने में देखा जा सकता है। इंटरनेट से जुड़ने के लिए एक कम्प्यूटर और एक मॉडम की आवश्यकता होती है। ये दुनिया की किसी भी जगह से पूरे विश्वभर की जानकारी ऑनलाइन प्राप्त करने में हमारी मदद करता है। इसके द्वारा हम वेबसाइट से कुछ ही सेकण्डों में जानकारी को प्राप्त करके भविष्य के लिए सुरक्षित कर सकते हैं। मेरे स्कूल के कम्प्यूटर लैब में इंटरनेट की सुविधा है जहाँ हम अपने प्रोजेक्ट से सम्बन्धित जरूरी जानकारी को प्राप्त कर सकते हैं।

उपयोग की दिशाएँ-इन्टरनेट से ऑनलाइन सम्पर्क तेज और आसान हो गया है जिससे संदेश या विडियो कॉनफ्रेंस के द्वारा दुनिया में कहीं भी मौजूद लोग एक-दूसरे से जुड़ सकते हैं। इसकी मदद से विद्यार्थी अपनी परीक्षा, प्रोजेक्ट तथा रचनात्मक कार्यों में भाग लेता है। इससे विद्यार्थी अपने शिक्षकों और दोस्तों से ऑनलाइन जुड़कर कई सारे विषयों पर चर्चा कर सकता है। इसकी सहायता से हम विश्व से सम्बन्धित कोई भी जानकारी प्राप्त कर सकते हैं जैसे कहीं की यात्रा के लिए उसके बारे में पता लगा सकते हैं।

इन्टरनेट कनेक्शन से जुड़ते ही हमारी पहँच वर्ल्ड वाइड वेब तक हो जाती है। पहले के समय में जब इंटरनेट नहीं था तो लोगों को कई प्रकार के कार्यों के लिए लंबे समय तक लाइन में लगना पड़ता था जैसे रेलवे का टिकट लेने के लिए, बिल जमा करने के लिए आदि लेकिन आधुनिक समय में लोग बस एक बटन को दबाते ही टिकट बुक कर सकते हैं तथा एक सॉफ्टकॉपी भी अपने मोबाइल में रख सकते हैं। हम इसे नेटवर्को का नेटवर्क कह सकते हैं।

दुरुपयोग के बिन्दु-इंटरनेट ने जीवन को आसान बना दिया है पर इसकी वजह से नुकसान भी हो रहे हैं। इंटरनेट पर हैकिंग, स्पैनिंग और अन्य ऐसी कुख्यात गतिविधियाँ भी होती हैं। कई छात्र इंटरनेट पर विभिन्न प्रकार की वीडियो देखते हैं तथा ऑनलाइन गेम खेलते हैं और इसके आदी हो जाते हैं। अधिक इस्तेमाल करने से स्वास्थ्य पर भी इसका विपरीत प्रभाव पड़ता है। इससे माइग्रेन, नेत्रदृष्टि पर प्रभाव, पीठ दर्द, वजन बढ़ना, डिप्रेशन, रिश्तों पर नकारात्मक प्रभाव आदि पड़ने लगता है।

समाधान व संदेश-इसके समाधान के लिए सोशल साइट के उपयोग के लिए एक सीमा निर्धारित कर देनी चाहिए। विद्यालयों में प्रोजेक्ट आदि बनाने की व्यवस्था होनी चाहिए। जिससे छात्र अध्यापक की निगरानी में प्रोजेक्ट बना सकें। अभिभावक भी अपने बच्चों द्वारा इन्टरनेट के उपयोग की अवधि निश्चित करें।

(ख) ग्लोबल वार्मिंग के खतरे

अर्थ-धरती के तापमान में लगातार बढ़ते स्तर को ग्लोबल वार्मिंग कहते हैं। वर्तमान समय में ये पूरे विश्व के समक्ष एक बड़ी समस्या के रूप में उभर रहा है। ऐसा माना जा रहा है कि धरती के वातावरण के गर्म होने का मुख्य कारण ग्रीनहाउस के स्तर में वृद्धि है। अगर इससे छुटकारा पाने के लिए कोई ठोस कदम नहीं उठाया गया तो वह दिन दूर नहीं कि धरती अपने अन्त की ओर अग्रसर होगी।

कारण व समस्याएँ-दिनों-दिन बढ़ते इसके खतरनाक प्रभाव से सम्पूर्ण विश्व के लिए खतरा उत्पन्न हो रहा है, इसके कारण समुद्र के जलस्तर में वृद्धि हो रही है, बाढ़, तूफान, चक्रवात, मौसम के स्वरूपों में परिवर्तन, संक्रामक बीमारियाँ, खाद्यान्न में कमी आदि आने वाले समय में दिखाई देंगी। इससे छुटकारा पाने का एक ही तरीका है व्यक्तिगत स्तर पर जन-जागरूकती। लोगों को इसका अर्थ, कारण और इससे होने वाले प्रभाव के बारे में समझना चाहिए और उससे बचने के उपाय ढूँढ़ने चाहिए, जिससे जीवन की संभावनाएँ सदा के लिए मुमकिन हो सके।

बचाव के उपाय-लोगों को उनकी आदतें जैसे तेल, कोयला और गैस के अत्यधिक इस्तेमाल, पेड़ों की कटाई को रोककर, कम बिजली का इस्तेमाल करके CO2 को फैलने से रोकना चाहिए। पूरी दुनिया के लोगों में थोड़े से बदलाव से, एक दिन हम लोग इसके प्रभावों को घटाकर वातावरण में हुए नकारात्मक परिवर्तनों को रोक सकते हैं।

समाधान व संदेश-पूरे विश्व में जनसंख्या विस्फोट को भी रोकने की आवश्यकता है क्योंकि इससे धरती पर विनाशकारी तकनीकों का इस्तेमाल कम होगा। हमें वातावरण में ग्रीनहाउस गैसों का कम से कम उत्सर्जन करना चाहिए और उन जलवायु परिवर्तनों को अपनाना चाहिए जो वर्षों से होते आ रहे हैं। तेल जलाने और कोयले के इस्तेमाल, परिवहन के साधनों और बिजली के सामानों के स्तर को घटाने से ग्लोबल वार्मिंग के प्रभाव को घटाया जा सकता है।

(ग) स्वच्छ भारत-एक कदम स्वच्छता की ओर

स्वच्छ भारत मिशन या स्वच्छ भारत अभियान भारत सरकार द्वारा चलाया गया एक विशाल जन-आन्दोलन है जोकि पूरे भारत में सफाई को बढ़ावा देता है। इस अभियान को 2 अक्टूबर, 2014 को महात्मा गाँधी की 150वीं वर्षगाँठ के दिन सुबह शुरू किया गया था। महात्मा गाँधी जी ने भारत को स्वच्छ बनाने का सपना देखा था और इसके लिए हमेशा कठिन प्रयास किए। उनके सपने को पूरा करने के लिए भारत सरकार ने इस अभियान को शुरू करने का फैसला किया। उत्तर प्रदेश के मुख्यमंत्री योगी आदित्यनाथ ने उत्तर प्रदेश सरकार के कार्यालयों में सफाई सुनिश्चित करने के लिए पान, गुटका और तम्बाकू उत्पादों के सेवन पर भी प्रतिबंध लगा दिया है। इस मिशन का उद्देश्य सभी ग्रामीण और शहरी क्षेत्रों को कवर करना है ताकि दुनिया के सामने हम एक आदर्श देश का उदाहरण प्रस्तुत कर सकें। इस मिशन के उद्देश्य में से कुछ महत्वपूर्ण उद्देश्य हैं-खुले में शौच समाप्त करना, अस्वास्थ्यकर शौचालयों को फ्लश शौचालयों में परिवर्तित करना, हाथ से मल की सफाई को रोकना, ठोस और तरल कचरे का पुन: उपयोग, लोगों को सफाई के प्रति जागरूक करना, अच्छी आदतों के लिए प्रेरित करना, शहरी और ग्रामीण क्षेत्रों में सफाई व्यवस्था अनुकूल बनाना व भारत में निवेश के लिए रुचि रखने वाले सभी निजी क्षेत्रों के लिए अनुकूल वातावरण प्रदान करना आदि।

इस तरह हम कह सकते हैं कि 2019 तक भारत को स्वच्छ और हरा-भरा बनाने के लिए स्वच्छ भारत अभियान एक स्वागत योग्य कदम है। जैसा कि हम सभी ने कहावत में सुना है स्वच्छता भगवान की ओर अगला कदम है। हम विश्वास के साथ कह सकते हैं कि अगर भारत की जनता द्वारा प्रभावी रूप से इसका अनुसरण किया जाए तो आने वाले चंद वर्षों में स्वच्छ भारत अभियान से पूरा देश भगवान का निवास स्थल सा बन जाएगा।

उत्तर 13. सेवा में,
प्रधान संपादक महोदय,
दैनिक हिन्दुस्तान,
नई दिल्ली।
दिनांक-2 फरवरी 20xx
विषय-नगर में बढ़ते जा रहे अवैध निर्माण के संदर्भ में ।

मान्यवर महोदय,
मैं इस पत्र के माध्यम से आपका तथा प्रशासन का ध्यान अपने नगर में बढ़ते जा रहे अवैध निर्माण की ओर आकर्षित करना चाहता हूँ। पिछले कई वर्षों से ये अवैध निर्माण चारों तरफ अपना प्रसार कर रहे हैं। मुख्य सड़क पर दुकानदारों ने अपनी दुकान इतनी आगे बढ़ा ली है कि सड़क पर चलना मुश्किल हो गया है। जाम लगने के कारण कई घंटों तक मार्ग अवरुद्ध हो जाता है। वाहनों की मरम्मत से जुड़ी दुकानों ने तो लोगों की नाक में दम कर रखा है। होटलों, मैरिज होम तथा वाहन विक्रेताओं ने अवैध निर्माण में कोई असर नहीं छोड़ी। है। अत: प्रशासन से मेरा अनुरोध है कि ऐसे अवैध निर्माण तुरन्त रेखांकित किए जाएँ और उन्हें हटाने की अन्तिम तिथि घोषित कर दें और न हटाने पर कड़ी कार्यवाही की जाए।

धन्यवाद!
भवदीय,
क.ख.ग
अ.ब.स. नगर, आगरा

अथवा

प्रतिष्ठा में,
डाकपाल महोदय,
जी. पी. ओ. गाजियाबाद
उत्तर प्रदेश
दिनांक : 21 जून 20xx
विषय-डाक विभाग की अव्यवस्था के संदर्भ में पत्र।
महोदय,
मैं क.ख.ग. शास्त्रीनगर, गाजियाबाद का निवासी हूँ। इस पत्र द्वारा में डाक विभाग के डाक वितरण की अव्यवस्था की ओर आपका ध्यान आकर्षित करना चाहता हूँ।

हमारे क्षेत्र का डाकिया अपना कार्य ठीक प्रकार से नहीं कर रहा है। उसके आने-जाने का कोई निश्चित समय नहीं है। यही नहीं कभी-कभी तो वह पत्र किसी दूसरे को पकड़ा जाता है या घर के पास फेंक जाता है। इस कारण कभी-कभी आवश्यक पत्र या बिल खो जाते हैं। मैंने कई बार उसको समझाने की कोशिश की लेकिन उसका कोई भी परिणाम नहीं निकला।

आपसे निवेदन है कि या तो आप इनके खिलाफ कोई कार्यवाही करें या किसी दूसरे डाकिए का प्रबन्ध कर दें।
धन्यवाद
भवदीय
क.ख.ग
9A-495 शास्त्रीनगर, गाजियाबाद।

उत्तर 14.

We hope the CBSE Sample Papers for Class 10 Hindi A Set 1 help you. If you have any query regarding CBSE Sample Papers for Class 10 Hindi A Set 1, drop a comment below and we will get back to you at the earliest.

CBSE Sample Papers for Class 10 Science Paper 10

These Sample papers are part of CBSE Sample Papers for Class 10 Science. Here we have given CBSE Sample Papers for Class 10 Science Paper 10.

Time allowed : 3 hours
Maximum marks : 80

General Instructions

• The question paper comprises two sections, A and B. You are to attempt both the sections.
• All questions are compulsory.
• All questions of Section-A and B are to be attempted separately.
• There is an internal choice in two questions of three marks each and one question of five marks.
• Question numbers 1 and 2 in Section-A are one mark question. They are to be answered in one word or in one sentence.
• Question numbers 3 to 5 in Section-A are two marks questions. These are to be answered in 30 words each.
• Question numbers 6 to 15 in Section-A are three marks questions. These are to be answered in about 50 words each.
• Question numbers 16 to 21 in Section-A are 5 mark questions. These are to be answered in 70 words each.
• Question numbers 22 to 27 in Section-B are based on practical skills. Each question is a two marks question. These are to be answered in brief.

SECTION – A

Question. 1.
What category of diseases does AIDS come under ? Name its causative organism.

Question. 2.
Name the method by which Spirogyra reproduces under favourable conditions. Is this method sexual or asexual ?

Question. 3.
Dry hydrogen chloride gas does not turn blue litmus red whereas hydrochloric acid does. Give one reason.

Question. 4.
How can you distinguish between a plane mirror, a concave mirror and a convex mirror without touching them ?

Question. 5.
Where does the digestion of fat take place in our bodies ?

Question. 6.
A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is

(a) pushed into the coil
(b) withdrawn from inside the coil
(c) held stationary inside the coil ?

OR
Two circular coils A and B are placed close to each other. If the current in the coil A is changed, will some current be induced in the coil B ? Give reason.

Question. 7.
Why is an ammeter likely to bum out if you connect it in parallel ?

Question. 8.
(a) What were the two major shortcomings of Mendeleev’s periodic table. How have these been removed in the modem periodic table ?
(b) Two elements X and Y have atomic numbers 12 and 16 respectively. Write the electronic configuration for these elements. To which period of the modem periodic table do these two elements belong ? What type of bond formed between them and why ?

Question. 9.
If the water supply at home requires a large amount of soap what do you infer ? Why does this happen ?

Question. 10.
What is biological magnification ? Are human beings affected by it ?

Question. 11.
What is the role of platelets in the human body ?

Question. 12.
An object placed on a meter scale at 8 cm mark was focussed on a white screen placed at 92 cm mark, using a converging lens placed on the scale at 50 cm mark.

(a) Find the focal length of the converging lens.
(b) Find the position of the image formed if the object is shifted towards the lens at a position of 29 cm.
(c) State the nature of the image formed if the object is further shifted towards the lens.

Question. 13.
Why do acids show acidic behaviour only in the presence of water ?
OR
A lowering of pH of the mouth is a major cause for tooth decay. Elaborate on this.

Question. 14.
Describe the female reproductive part of the flower.

Question. 15.
What is sustainable natural resource management ?

Question. 16.
Describe an activity to show that the colours of white light splitted by a glass prism can be recombined to get white light by another identical glass prism. Also draw ray diagram to show the recombination of the spectrum of white light.

Question. 17.
What are structural isomers ? Explain with examples.
OR
(a) What are hydrocarbons ? Give one example.
(b) Give the structural differences between saturated and unsaturated hydrocarbons with two examples each.|
(c) What is a functional group ? Give examples of two different functional groups.

Question. 18.
(a) Draw a neat labelled diagram showing the different endocrine glands in the human body.
(b) What happens when adrenaline is released into the blood ? Is it correct to call this hormone as the ‘fight or flight hormone’.

Question. 19.
Draw a labelled circuit diagram showing three resistors R₁, R₂ and R₃ connected in series with a battery (E), a rheostat (Rh), a plug key (K) and an ammeter (A) using standard circuit symbol. Use this circuit to show that the same current flows through every part of the circuit. List two precautions you would observe while performing the experiment.

Question. 20.
How are ionic compounds formed ? Give their characteristics.

Question. 21.
What is the importance of forest as a resource ? What are the causes of deforestation ?
OR
Biomass is a good source of energy. Biogas is an excellent fuel. Elaborate.

SECTION – B

Question. 22.
If we pour acetic acid on red litmus paper and blue litmus paper, what happens ?

(a) Red litmus remains red and blue litmus turns red.
(b) Red litmus turns blue and blue litmus remains blue.
(c) Red litmus turns blue and blue litmus turns red.
(d) Red litmus turns colourless and blue litmus remains blue.

Question. 23.
While demonstrating decomposition reaction in the laboratory the teacher heated ferrous sulphate crystals in a hard glass dry boiling tube.
(a) What will be the smell of gases coming out of the boiling tube ?
(b) What will be the change in colour of the ferrous sulphate crystals ?

Question. 24.
Draw a labelled diagram of the cross-section of a leaf peel showing stomata.

Question. 25.
When you perform the experiment to show that CO₂ is given out during respiration how will you confirm the gas evolved is CO₂ ?

Question. 26.
The rest positions of the needles in a milliammeter and voltmeter not in use are as shown in Fig. A. When a student uses these in his experiment, the readings of the needle are in the positions shown in Fig. B.

Find the corrected values of current and voltage in the experiment.
OR
The following circuit diagram shows the experimental set-up for the study of dependence of current on potential difference. Which two circuit components are connected in series ?

Question. 27.
The teacher asks a student to fix the given screen at an appropriate place in the given experimental set up, so that a clear image can be obtained on the screen. If the focal length of convex lens in 8 cm, find the mark on the scale at which he should fix up the screen ?

ANSWERS

SECTION – A

Answer. 1.
AIDS comes under viral diseases which are sexually transmitted. It stands for Acquired Immuno Deficiency Syndrome and is caused by the Human Immuno Deficiency virus also called HIV virus.

Answer. 2.
Under favourable conditions, Spirogyra reproduces by fragmentation. This is an asexual method of reproduction.

Answer. 3.
Acids produce hydrogen ions [H⁺(aq)] in solution which are responsible for turning blue litmus red. Dry HCl does not give H⁺ ions in the absence of water.

Answer. 4.
By oberving the virtual images formed by the three mirrors, we can distinguish between the mirrors as :

1. Plane mirror will produce an image of the same size,
2. Concave mirror will produce a magnified image, and
3. Convex mirror will produce a diminished image.

Answer. 5.
The small intestine is the site of the complete digestion of carbohydrates, proteins and fats. It receives the secretions of the liver and pancreas for this purpose. The food coming from the stomach is acidic and has to be made alkaline for the pancreatic enzymes to act. Bile juice from the liver accomplishes this in addition to acting on fats. Fats are present in the intestine in the form of large globules which makes it difficult for enzymes to act on them. Bile salts break them down into smaller globules to help enzymes act efficiently on them. The pancreatic juice contains enzymes like trypsin for digesting proteins and lipase for digesting emulsified fats. The enzymes in the intestinal juice secreted by the small intestine convert the proteins into amino acids, complex carbohydrates into glucose and fats into fatty acid and glycerol.

Answer. 6.
(a) When a bar magnet is pushed into the coil of insulated copper wire connected to a galvanometer, an induced current is set up in the coil. As a result, galvanometer gives a deflection (say towards left).
(b) When the bar magnet is withdrawn from inside the coil, again an induced current is set up in the coil. However, now direction of induced current is opposite to that in earlier case. Hence, deflection in galvanometer is in reverse direction (say towards right).
(c) If the bar magnet is held stationary inside the coil, then there is no induced current in the coil. As a result, galvanometer does not show any deflection.
OR
Yes, a current is induced in the coil B.
When the current in the coil A is changed, the magnetic field associated with it also changes. As coil B is placed close to A, hence magnetic field lines around this coil also change. Due to change in magnetic field lines associated with coil B, an induced current is also induced in it.

Answer. 7.
An ammeter has a very low resistance and is used to measure electric current flowing in a circuit. If an ammeter is connected in parallel with an electrical circuits, the net resistance of circuit becomes even less than the resistance of an ammeter and a strong current begins to flow. As a result the ammeter is likely to bum out.
(a) Two major shortcomings of Mendeleev’s periodic table :

1. The position of isotopes could not be explained.
2. Wrong order of atomic masses of some elements could not be explained.

In the modem periodic table, the elements are arranged in the increasing order of their atomic numbers instead of atomic masses.

(b) Atomic number of element X = 12
Electronic configuration = 2,8,2 KLM
Atomic number of element Y = 16
Electronic configuration = 2,8,6 KLM
The period number of an element is equal to the number of electron shells in its atom. These two elements have 3 electron shells, therefore they belong to 3rd period.

They will form ionic bond because X is a metal and Y is a non-metal. X loses two electrons which will be gained by Y.

Answer. 9.
If the water supply at home requires a large amount of water it means the water is hard i.e., it contains salts of calcium and magnesium. Usually the salts of calcium and magnesium cause hardness of water. Such type of water does not lather with soap. While bathing with hard water foam is formed with difficulty and an insoluble substance (scum) remains after washing with the water. This problem can be overcome by using another class of compounds called detergents as cleansing agents. Detergents are generally ammonium or sulphate salts of long chain carboxylic acids. The charged ends of these compounds do not form insoluble precipitates with the calcium and magnesium ions in hard water. Thus, they remain effective in hard water. Detergents are usually used to make shampoos and products for cleaning clothes.

Answer. 10.
Human beings are on top of any food chain. This means the maximum concentration of several harmful chemicals get accumulated in the human bodies. This is also called biological magnification. We have seen how water is polluted by different substances. Pesticides and some chemicals are used to protect crops from pests. These enter the soil and the water that flows on this soil. When this water is absorbed by the roots of plants it enters the plants. Similarly when aquatic animals drink water some chemicals enter their bodies too. These chemicals then enter the food chain. As they are not degraded they are gradually accumulated in each trophic level. Finally all of them reach the human bodies. Food grains like rice, wheat, vegetables, fruits, and meat contain varying amounts of pesticide residues. It is difficult to completely remove them by washing. Hence any organism at the top of the food chain is likely to get a fairly large amount of the harmful substances that enter the food chain at every level. So the effect of the various pollutants is maximised in human beings.

Answer. 11.
Platelets or thrombocytes are one of the constituents of blood the other two being the red blood,corpuscles or erythrocytes and white blood corpuscles or leucocytes. Whenever there is an injury in the body bleeding starts. The body cannot afford to lose blood. In addition, leakage of blood leads to a drop in pressure which affects the pumping of the heart. To avoid this, the body immediately informs the platelets to reach the site of injury. The platelets that keep circulating in the body quickly reach the site of bleeding and form a barrier or plug which stops the bleeding. That is why platelets,are needed by our body.

Answer. 12.
(a) Here position of object on meter scale = 8 cm, position of converging (convex) lens = 50 cm and position of screen = 92 cm.
u = (50 – 8) = 42 cm and υ = (92 – 50) = 42 cm
As per sign convention, u = – 42 cm and υ = + 42 cm.

(b) If object is shifted to a position 29 cm, then u’ = (50 – 29) cm = 21 cm i.e., the object is situated at first focus Fa of the lens. Hence its real and inverted image is formed at infinity.
(c) If the object is further shifted towards the lens then | u | <f and hence a virtual and erect image of the obj ect will be formed.

Answer. 13.
Acids do not show acidic behaviour in the absence of water. This is because the H+ ions are produced only in the presence of water. The H+ ions cannot exist alone but they exist only after combining with water molecules.
If water is added to HCI the reaction occurs as follows :
HCI + H2O → H₃O⁺ + Cl^–
The separation of H+ ions from the HCI molecule cannot occur in the absence of water. The process of dissolving acid in water is highly exothermic. The acid must be slowly added to the water with constant stirring, water must not be added to the acid.
OR
A lowering of the pH of the mouth means the environment inside the mouth is turning acidic. We have learnt that when the pH is less than 7 the said material or solution is acidic. When acids are formed in the mouth due to the deposit of leftover food particles between the teeth it leads to a slow destruction of the enamel of the teeth. Initially it appears as a black spot but soon it grows in size and destroys the entire enamel. Once the enamel is removed the nerves and blood vessels under the teeth are exposed. This is when we experience severe pain whenever anything hot or cold is ingested.

Answer. 14.
The carpel is the female reproductive part of the flower which is present in the centre of the flower. It consists of three parts. The upper part which is sticky and is called the stigma, the middle elongated part is called the style and the swollen bottom part is called ovary. The ovary contains the ovules and each ovule has an egg inside. The male germ-cell produced by the pollen grain fuses with the female germ cell in the ovule. This is called fertilisation and it results in the formation of the zygote. This zygote grows into a new plant.

Answer. 15.
All the things we use or consume like food, clothes, our shelter, books, toys, furniture, tools and vehicles are obtained from resources on this earth. The only thing we get from outside is the energy from the sun. This too is processed by the living organisms and various physical and chemical processes on the earth before we can use it. We should use resources judiciously because they are limited. We have an ever-increasing human population due to improved health care and this has brought about an increased demand for all the resources. The management of natural resources requires a long-time perspective so that they will last for the future generations and will not be exploited over a short period of time. Resource management must be focussed on an equitable distribution of resources so that it is not just a handful of rich and powerful people who benefit from this. In addition, when we extract these resources we must ensure a safe disposal of the wastes too. This is called sustainable natural resource management.

Answer. 16.
Recombination of colours: The colours of white light splitted by a glass prism can be recombined to get white light by another identical glass prism. Newton demonstrated this phenomenon of recombination of the coloured rays of a spectrum to get back white light.

1. A triangular prism ABC is placed on its base BC.
2. A similar prism A’B’C’ is placed alongside with its refracting surface in the opposite direction, i.e., in an inverted position with respect to first prism as shown in figure.
   
3. A beam of white light entering the prism ABC undergoes refraction and is dispersed into its constituent seven colours.
4. These constituent seven coloured rays are incident on the second inverted prism A’B’C’ and get further refracted.
5. The second prism recombines them into a beam of white light and emerges from the other side of the second prism and falls on the screen.
6. This is due to the fact that the refraction or bending produced by the second inverted prism is equal and opposite to the refraction or bending produced by the first prism. This causes the seven colours to recombine.
7. A white patch of light is formed on the screen placed beyond the second prism. This proves the phenomenon of recombination of spectrum of white light.

Answer. 17.
Structural isomers are carbon compounds that have the same or identical molecular formula but different structural formula. An example of structural isomers is shown below :

In addition to straight and branched carbon chains, some compounds have carbon atoms arranged in the form of a ring. Carbon has the unique ability to form bonds with other atoms of carbon giving rise to large molecules. This property is called catenation. We can find compounds with long chains of carbon or even carbon atoms arranged in a ring. In addition carbon atoms can be linked by single, double or triple bonds. As carbon is tetravalent it forms covalent bonds with four other atoms of carbon or atoms of some other monovalent element. These bonds are very strong and so the elements are very stable. Compounds of carbon which are linked by only single bonds between carbon atom are called saturated compounds. Compounds of carbon having double or triple bonds between their carbon atoms are called unsaturated compounds.
OR
(a) Compounds of carbon and hydrogen are called hydrocarbons, e.g., methane, ethane, etc.
(b) Saturated hydrocarbons contains carbon-carbon single bonds, e.g., methane, ethane. Unsaturated hydrocarbons contain atleast one carbon-carbon double or triple bond, e.g., ethene, ethyne.
(c) Functional group is an atom or group of atoms joined in a specific manner which is responsible for the characteristics properties of the organic compounds, e.g., OH, – CHO.

Answer. 18.

(b) Hormones are chemical substances secreted by ductless or endocrine glands in the body. One such hormone is adrenaline. It is secreted by the adrenal glands which areb present just above the kidneys. Adrenaline is directly released into the blood and carried to different parts of the body. The target organs on which it acts includes the heart. As a result, the heart beats faster, resulting in supply of more oxygen to our muscles. The blood to the digestive system and skin is reduced due to contraction of muscles around small arteries in these organs. This diverts the blood to the skeletal muscles. There is an increase in the breathing rate too. All these responses make the animal body ready to face the situation. The animal either faces the situation or flees from danger. Hence adrenaline is called the fight or flight hormone.

Answer. 19.

Aim : Same current flows through every part of the above circuit.
Procedure :

1. Connect the another ammeters, ‘A₁‘ between B and C, and ‘A₂‘ between D and E.
2. Adjust the sliding contact ‘j’ of the rheostat initially for a small current.
3. Note all the ammeter readings. This reading gives us current flowing through the resistors R₁,R₂ and R₃.
4. The current in the circuit is now increased by changing the position of sliding contact ‘j’ of the rheostat.
5. Note all the ammeter readings each time.

Conclusion : Same reading of all the ammeter in each observation concluded that same current flows through every part of the circuit.

Precautions:

1. All the connection should be tight and properly connected as per circuit diagram.
2. The positive terminal of the ammeter and voltmeter must be connected to the positive terminal of the battery or battery eliminator.

Answer. 20.
Ionic compounds are formed by the transfer of electrons from one atom to another in an effort to get the stable electronic configuration in their outermost shell. The bond formed is called electrovalent bond and the atoms in that are either positive or negative ions. These ions are held together by strong forces of attraction. Hence ionic compounds are usually solids.

1. Ionic compounds have high melting and boiling points this means a lot of energy is required to break the strong inter-ionic attraction.
2. A solution of ionic compounds contains ions which move to the oppositely charged electrodes when current passes through the solution. Ionic compounds do not conduct electricity in the solid state as ions cannot move about. Ionic compounds conduct electricity in the molten state as the electrostatic forces between the ions is overcome by the heat.

Answer. 21.
Forests are an important natural resource due to following reasons :

1. Forests provide us wood, dry fruits, spices, gums, resins, dyes, tannins and various products like honey, camphour, rubber etc.
2. The roots of trees hold the soil firmly preventing soil erosion.
3. It absorbs carbon dioxide from atmosphere and release oxygen which is life supporter.
4. It absorbs carbon dioxide which is a greenhousfe gas thus plays an important role in reducing global warming.
5. It increases frequency of rainfall and regulates water cycle.
6. It serves as a shelter for wildlife.

Causes of deforestation are :

1. Large scale deforestation for demand of wood, timber as raw materials for industries, domestic purposes etc.
2. Construction of dams, reservoirs, roads, railways.
3. Setting up of factories and industries.
4. Construction of big apartments to provide space to the growing population.
5. Shifting cultivation for agriculture.
6. Overgrazing by livestock.

OR
While looking at the conventional sources of energy a number of points can be considered. Wood has been used as a fuel for a long time. This can continue if only we have enough trees around to provide a continuous supply of wood. Even cow-dung cakes are used as fuel. With a large livestock population in our country cow-dung cake can also be used as a steady source of fuel. As both these fuels are from plant and animal products, the source of these fuels is said to be biomass. These fuels, however, do not produce much heat on burning and a lot of smoke is given out when they are burnt. So, one has to look out for new technological inputs to improve the efficiency of these fuels. When wood is burnt in a limited supply of oxygen, water and other volatile substances in it are removed and only charcoal is left behind as residue. Charcoal bums without flames, is comparatively smokeless and has higher heat generation efficiency.

Cow-dung, plant residue after harvesting of crops, vegetable waste and sewage are decomposed in the absence of oxygen to give bio-gas. As the starting material is mainly cow-dung, it is popularly known as gobar-gas. Biogas is produced in the biogas plant biogas is an excellent fuel as it contains upto 75% methane. It bums without smoke, leaves no residue like ash in wood, charcoal and coal burning. Its heating capacity is high. Biogas is also used for lighting. The slurry left behind is removed periodically and is used as excellent manure, rich in nitrogen and phosphorous. The large-scale utilization of bio¬waste and sewage material provides a safe and efficient method of waste-disposal besides supplying energy and manure.

SECTION – B

Answer. 22.
(a) Red litmus remains red and blue litmus turns red.

Answer. 23.
(a) There will be no smell of gases coming out of the boiling tube.
(b) The light green crystals of ferrous sulphate will turn white in colour.

Answer. 24.

Answer. 25.
The gas that is collected at the end of the process is allowed to pass through lime water. When lime water turns milky it is a confirmation that the gas is CO₂.

Answer. 26.
Milliammeter has negative zero error and voltmeter has positive zero error.
Zero correction is always, negative of zero error.
∴ Milliammeter reading = 38 – (- 4) = 38 + 4 = 42 mA
Voltmeter reading = 3.6 – (+ 0.4)
= 3.6 – 0.4 = 3.2 V
OR
Ammeter and rheostat are connected in series.
This is because only one common point exists between ammeter, cell and rheostat.

Answer. 27.
When the object is at infinity from a convex lens, then the image formed is at focus (on the other side of the lens). The lens with stand is fixed at 5.8 cm. The focal length of convex lens is 8 cm. Therefore, he should fix up the screen at 13.8 cm mark on the scale.

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NCERT Solutions for Class 10 Science Chapter 8 How do Organisms Reproduce (Hindi Medium)

These Solutions are part of NCERT Solutions for Class 10 Science in Hindi Medium. Here we have given NCERT Solutions for Class 10 Science Chapter 8 How do Organisms Reproduce.

Chapter 8. जीव जनन कैसे करते है

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