2022 Class 10 Science Paper CBSE: Previous Year Questions with Answers

CBSE Class 10 Science 2022 Board Paper – Questions and Solutions

Class 10 Science Previuos Year Question and Answer 2022

★ Please check that this question paper contains 15 printed pages.

★ Q.P. Code given on the right hand side of the question paper should be written on the title page of the answer-book by the candidate.

★ Please check that this question paper contains 15 questions.

★ Please write down the serial number of the question in the answer-book before attempting it.

★ 15 minute time has been allotted to read this question paper. The question paper will be distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period.

SCIENCE

Time allowed : 2 hours Maximum Marks : 40

General Instructions :

Read the following instructions very carefully and strictly follow them :

(i) This question paper comprises 15 questions. All questions are compulsory.

(ii) This question paper is divided into three sections A, B and C.

(iii) Section A Questions No. 1 to 7 are short answer type questions. Each question carries 2 marks.

(iv) Section B Questions No. 8 to 13 are also short answer type questions. Each question carries 3 marks.

(v) Section C Questions No. 14 and 15 are case-based questions. Each question carries 4 marks.

(vi) Internal choices have been provided in some questions. Only one of the alternatives has to be attempted.

SECTION = A

1. (a) Write the molecular formula of the following carbon compounds :

(i) Methane

(ii) Propane

(b) Carbon compounds have low melting and boiling points. Why ? 2

2. The electrons in the atoms of two elements X and Y are distributed in three shells having 1 and 7 electrons respectively in their outermost shells.

(a) Write the group numbers of these elements in the Modern Periodic Table.

(b) Write the molecular formula of the compound formed when X and Y combine with each other.

3. (a) Which of the following flowers will have higher possibility of self-pollination ?

Mustard, Papaya, Watermelon, Hibiscus

(b) List the two reproductive parts of a bisexual flower. 2

4. Which one of the two multicellular organisms Spirogyra and Planaria reproduces by regeneration and why ? Give an example of any other organism which can also reproduce by the same process. 2

5. (a) What is variation ? List two main reasons that may lead to variation in a population. 2

(b) (i) In a cross between violet flowered plants and white flowered plants, state the characteristics of the plants obtained in the F1 progeny.

(ii) If the plants of F1 progeny are self-pollinated, then what would be observed in the plants of F2 progeny ?

(iii) If 100 plants are produced in F2 progeny, then how many plants will show the recessive trait ? 2

6. (a) (i) Name and state the rule to determine the direction of force experienced by a current carrying straight conductor placed in a uniform magnetic field which is perpendicular to it.

(ii) An alpha particle while passing through a magnetic field gets projected towards north. In which direction will an electron project when it passes through the same magnetic field ?

(b) (i) What is a solenoid ?

(ii) Draw the pattern of magnetic field lines of the magnetic field produced by a solenoid through which a steady current flows. 2

7. (a) What is ozone ? How is it formed in the upper layers of the Earth’s atmosphere ? How does ozone affect our ecosystem ? 2

(b) (i) List two human-made ecosystems. 1

(ii) “We do not clean a pond in the same manner as we do in an aquarium ”.Give reason to justify this statement . 1

SECTION = B

8. (a) List two advantages of adopting the atomic number of an element as the basis of classification of elements in the Modern Periodic Table.

(b) Write the electronic configurations of the elements X (atomic number 13) and Y (atomic number 20). 3

9. (a) Draw two different possible structures of a saturated hydrocarbon having four carbon atoms in its molecule. What are these two structures of the hydrocarbon having same molecular formula called ? Write the molecular formula and the common name of this compound. Also write the molecular formula of its alkyne. 3

(b) (i) Write the molecular formula of benzene and draw its structure.

(ii) Write the number of single and double covalent bonds present in a molecule of benzene.

(iii) Which compounds are called alkynes ? 3

10. (a) Mention one function each of the following organs in human male reproductive system :

(i) Testis

(ii) Scrotum

(iii) Vas deferens

(iv) Prostate gland

(b) Name the type of germ cell which (i) is motile, and (ii) stores food. 3

11. (a) Three resistors and are connected in parallel and the combination is connected to a battery, an ammeter, a voltmeter and a key. Draw suitable circuit diagram to show the arrangement of these circuit components along with the direction of current flowing.

(b) Calculate the equivalent resistance of the following network : 3

Photo

12. (a) (i) Define Electric Power and write its SI unit. [1/2 + ½]

(ii) Two bulbs rated 100 W; 220 V and 60 W; 220 V are connected in parallel to an electric mains of 220 V. Find the current drawn by the bulbs from the mains. 2

(b) (i) State Joule’s law of heating . Express it mathematically when an appliance of resistance R is connected to a source of voltage V and the current I flows through the appliance for a time t .

(ii) A 5Ω resistor is connected across a battery of 6 volts. Calculate the energy that dissipates as heat in 10 s. 3

13. (a) Name the group of organisms which form in the first trophic level of all food chains. Why are they called so ?

(b) Why are the human beings most adversely affected by bio-magnification ?

SECTION = C

This section has 2 case-based questions (14 and 15). Each case is followed by 3 sub-questions (a), (b) and (c). Parts (a) and (b) are compulsory. However, an internal choice has been provided in Part (c).

14. The mechanism by which the sex of an individual is determined is called sex-determination. In human beings, sex of a newborn is genetically determined, whereas in some others it is not. There are 46 (23 pairs) chromosomes in human beings. Out of these, 44 (22 pairs) control the body characters and 2 (one pair) are known as sex chromosomes. The sex chromosomes are of two types X chromosome and Y chromosome. At the time of fertilisation, depending upon which type of male gamete fuses with the female gamete, the sex of the newborn child is decided.

(a) Why is a pair of sex chromosomes in human beings called a mismatched pair in terms of type and size ? [1/2+1/2 ]

(b) Out of male or female, which of them has a perfect pair of sex chromosomes ? In case of a perfect pair, will the gametes produced be of the same kind or of a different kind ? 1

(ii) With the help of a flowchart only, show how sex is genetically determined in human beings. 1+1

15. A student fixes a sheet of white paper on a drawing board using some adhesive materials. She places a bar magnet in the centre of it and sprinkles some iron filings uniformly around the bar magnet using a salt-sprinkler. On tapping the board gently, she observes that the iron filings have arranged themselves in a particular pattern.

(a) Draw a diagram to show this pattern of iron filings. 1

(b) Draw the magnetic field lines of a bar magnet showing the poles of the bar magnet as well as the direction of the magnetic field lines. 1

(c) (i) How is the direction of magnetic field at a point determined using the field lines ? Why do two magnetic field lines not cross each other ? 2

(ii) How are the magnetic field lines of a bar magnet drawn using a small compass needle ? Draw one magnetic field line each on both sides of the magnet.

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Class 10 Science Compartment Previuos Year Question and Answer 2022

SCIENCE (Set - 1)

★ Please check that this question paper contains 15 printed pages.

★ Q.P. Code given on the right hand side of the question paper should be written on the title page of the answer-book by the candidate.

★ Please check that this question paper contains 15 questions.

★ Please write down the serial number of the question in the answer-book before attempting it.

Time allowed : 2 hours Maximum Marks : 40

General Instructions :

Read the following instructions very carefully and strictly follow them :

(i) This question paper comprises 15 questions. All questions are compulsory.

(ii) This question paper is divided into three sections A, B and C.

(iii) Section A Questions No. 1 to 7 are short answer type questions. Each question carries 2 marks.

(iv) Section B Questions No. 8 to 13 are also short answer type questions. Each question carries 3 marks.

(v) Section C Questions No. 14 and 15 are case-based questions. Each question carries 4 marks.

(vi) Internal choices have been provided in some questions. Only one of the alternatives has to be attempted.

SECTION = A

1. Draw the electron dot structure of the molecules of (a) Oxygen, and

(b) Nitrogen. The atomic numbers of oxygen and nitrogen are 8 and 7 respectively. 2

2. (a) Arrange the following elements of 2nd period in the increasing order of their atomic radii :

F (9), Li (3), Be (4), N (7)

The atomic numbers of the elements are given in parenthesis. [2M]

(b) Determine the valency of an element ‘X’ belonging to Group number 13 and Period number 3 and write the formula of the Chloride of ‘X’ . [2M]

3. How is the number of chromosomes in the progeny of sexually reproducing organisms re-established ? Explain. [2M]

4. Name the parts A, B and C of the diagram given below. Write a function of the part B.

Photo

5. (a) Sex chromosomes in human males and females are XY and XX respectively. Statistical probability of getting either a male or a female child is 50%. Justify this statement giving reason. 2

(b) If we cross a tall plant (Tt) with a short plant (tt), what ratio of (Tt) and (tt) plants shall we obtain in F2 generation ? Show with the help of a diagram (flow chart) only. [2M]

6. (a) (i) A magnetic compass shows a deflection when placed near a current carrying wire. How will the deflection of the compass get affected if the current in the wire is increased ? What does it indicate ?

(ii) State Right hand thumb rule. [2M]

6. (b) List two factors on which the strength of magnetic field at a point due to a current carrying straight conductor depends. State the rule that determines the direction of magnetic field produced in this case. [2M]

7. (a) (i) Why are crop fields considered as artificial ecosystems ?

(ii) Write a common food chain of four steps operating in a terrestrial ecosystem. [2M]

7. (b) (i) Why should biodegradable and non-biodegradable wastes be discarded separately ?

(ii) What destructive effect do chlorofluorocarbons bring about in the atmosphere and to the mankind ? [2M]

SECTION = B

8. (a) State the basis of Döbereiner’s classification of elements.

(b) What was the limitation of Döbereiner’s classification

(c) In which group of Mendeleev’s Periodic Table should elements ‘X’ and ‘Y’ with molecular formulae (i) and (ii) be placed ? [3M]

9. (a) (i) In the given below compound

H H

| |

H – C – C – O – H

| |

H H

identify (I) the heteroatom, and (II) the functional group.

(ii) Write the structural formula of butane ().

(iii) Draw the complete structure of the molecule of (I) Cyclohexane, and (II) Benzene.

Which of the two is unsaturated ? [3M]

9.(b) (i) A compound with molecular formula has two isomers.

(I) Draw the structures of both the isomers.

(II) Write their functional group.

(ii) Why are the compounds of carbon exceptionally stable ? [3M]

10. What is vegetative propagation ? Name two methods in which this process is used to grow many plants. List any two advantages of vegetative propagation. [3M]

11. (a) (i) In the following figure, three cylindrical conductors A, B and C are shown along with their lengths and areas of cross-section.

Photo

If these three conductors are made of the same material and and be their respective resistances, then find (I) , and (II) .

(ii) If the conductor A is made of copper and the conductor C is made of constantan (alloy of copper and nickel), then which one of the two will have more electrical resistance and why ? [3M]

11.(b) (i) Write the formula for determining the equivalent resistance between A and B of the two combinations (I) and (II) of three resistors and arranged as follows :

Photo

(ii) If the equivalent resistance of the arrangements (I) and (II) are and respectively, then which one of the following V – I graphs is correctly labelled ? Justify your answer. [3M]

Photo

12. Define the term electric power. An electric device of resistance R when connected across an electric source of voltage V draws a current I. Derive an expression for the power in terms of resistance R and voltage V. What is the power of a device of resistance 400Ω operating at 200 V ? [3M]

13. Give reasons for the following : [3M]

(a) The existence of decomposers is essential in a biosphere.

(b) Flow of energy is unidirectional in a food chain.

SECTION C

14. A student crossed pea plants having round and yellow seeds with pea plants having wrinkled and green seeds. He found that only one type of seeds were produced in the F1 generation. When these F1 generation pea plants were self-pollinated with each other, then in addition to the seed type of F1 generation, some new types of seed combinations were also obtained in the F2 generation.

(a) Mention the dominant traits observed in F1 generation.

(b) What are the new possible combinations of seeds likely to be observed in F2 generation ?

(c) (i) Give reason why the traits which were not visible in the seeds of F1 generation reappeared in the seeds of F2 generation. Write the ratio of different types of seeds obtained in F2 generation in this case.

(ii) What is meant by the terms (I) dominant, and (II) recessive traits ? Explain.

15. Take two different coils of copper wire having large number of turns, say 50 and 100 turns respectively. Insert them over a non-conducting roll as shown in the given figure. Connect the Coil-1, having large number of turns, in series with a battery and a plug key. Also connect the other

Coil-2 with a galvanometer.

Photo

(a) State what is observed in the galvanometer, when

(i) the key is closed.

(ii) the key is opened.

(b) Define the phenomenon involved in this case.

(ii) A coil AB of copper wire is connected to a galvanometer as shown in the figure. What is observed when N-pole of a strong bar magnet is

(I) pushed into the coil, and

(II) held stationary inside the coil ? State the reason for each observation. [4M]

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Class 10 Science Previous Year Question and Answer 2022

(FOR VISUALLY IMPAIRED CANDIDATES ONLY)

Science , 2022

★ Please check that this question paper contains 11 printed pages.

★ Q.P. Code given on the right hand side of the question paper should be written on the title page of the answer-book by the candidate.

★ Please check that this question paper contains 15 questions.

★ Please write down the serial number of the question in the answer-book before attempting it.

Time allowed : 2 hours Maximum Marks : 40

General Instructions :

Read the following instructions very carefully and strictly follow them :

(i) This question paper comprises 15 questions. All questions are compulsory.

(ii) This question paper is divided into three sections A, B and C.

(iii) Section A Questions No. 1 to 7 are short-answer type questions. Each question carries 2 marks.

(iv) Section B Questions No. 8 to 13 are also short-answer type questions. Each question carries 3 marks.

(v) Section C Questions No. 14 and 15 are case-based questions. Each question carries 4 marks.

(vi) Internal choices have been provided in some questions. Only one of the alternatives has to be attempted.

SECTION = A

1. (a) What are Covalent Compounds ? List two properties of covalent compounds. 2

(b) “Carbon cannot form ionic bonds ”. Justify this statement .

2. Suppose three elements A , B and C form a Dobereiner’s tried.

List two properties which you would find in these three elements. 2

3. (a) What is Pistil (Carpel) ? State the main function of any two of its parts. 2

(b) What is Stamen ? State what happens when a pollen lands on a suitable stigma. 2

4. Explain briefly how vegetative propagation takes place in a ‘Bryophyllum ’ plant .

5. Pea plants were grown in two fields, X and Y. While field X produced pea plants with white flowers, field Y produced pea plants with blue flowers. In subsequent generations, it was observed that in the field X, the offsprings exhibited only the parental characters whereas in the field Y, majority of the offsprings exhibited variation in characters. State the possible reasons for these observations. 2

6. (a) What is a magnetic field ? How is the direction of a magnetic field at a place determined ? 2

(b) What is the pattern of the magnetic field lines produced by a current carrying straight conductor ? State the rule that determines the direction of the magnetic field in this case. 2

7. (a) What are Decomposers ? List two important roles of decomposers in an ecosystem. 2

(b) Distinguish between Biodegradable and Non-biodegradable substances giving one example for each. 2

SECTION = B

8. (a) (i) What is a Homologous Series ? Write the general formula of the homologous series for the compounds having functional group OH and give the molecular formula for the third member of this series.

(ii) Draw the structure of ethane and write the number of single bonds present in its molecule. 3

(b) (i) What are Structural Isomers ? Draw the structures of two isomers of butane ().

(ii) Write the molecular formula of (i) cyclohexane, and

(ii) benzene. 3

9. (a) State the Modern Periodic Law.

(b) How many vertical columns are there in the Modern Periodic Table ? What are they called ?

10. (a) Write the total number of chromosomes along with the sex chromosomes that are present in a human male and a human female. Explain how, in sexually reproducing organisms, the number of chromosomes in the progeny remains the same as that of the parent. 3

(b) Write the functions of the following parts of the human female reproductive system : 3

(i) Ovary

(ii) Fallopian tube

(iii) Uterus

11. (a) (i) What is a Solenoid ? What does the divergence of magnetic field lines near the ends of a current carrying solenoid indicate ?

(ii) How is an electromagnet made using a current carrying solenoid ? 3

(b) (i) State Fleming s left hand rule.

(ii) Write the principle of working of an electric motor.

(iii) Write the function of (i) brushes, and (ii) split ring in an electric motor. 3

12. Give reason for the following : 3

(a) Tungsten is used exclusively for the filaments of electric lamps.

(b) Heating elements of electric heating devices are made of alloys rather than a pure metal.

13. Define Trophic Level. Prepare a food chain comprising the following organisms :

Snakes, Plants, Hawks, Rats

If 1000 joules of energy is available at the first trophic level for transfer to the organisms of the second trophic level, then how much energy will be made available to the organisms at the fourth trophic level ? 3

SECTION = C

14. Mendel conducted breeding experiments with garden peas. He crossed tall pea plants (TT) with short pea plants (tt) and obtained only tall pea plants in F1 generation.

(a) List any two visible contrasting characters taken by Mendel in pea plants apart from height, in his other experiments.

(b) State the reason why only tall pea plants were obtained in the F1 generation.

(c) (i) When F1 generation pea plants were self-pollinated a total of 1600 plants were produced. How many of these plants of F2 generation would be (I) tall plants, and (II) short plants ? Give the gene (trait) combination of plants produced in F2 generation.

(ii) If a student performs the same experiment with other angiosperms and gets the similar results, then on the basis of his experiment, can he arrive at a conclusion ? If yes, write the conclusion. If not, give justification for your answer. 4

15. A student has designed an electric circuit containing a 6 V battery, a key, an ammeter, and a resistor of 30Ω in series with a parallel combination of two resistors of 60 Ω each and a voltmeter across the 30 Ω resistor.

(a) Find the equivalent resistance of the parallel combination of two 60 Ω resistors.

(b) Determine the total resistance of the circuit.

(ii) Will the potential difference across the 30 Ω resistor be the same as that across the parallel combination of two 60 Ω resistors ? Justify your answer.

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Class 10 Science Compartment Previuos Year Question and Answer 2022

(FOR VISUALLY IMPAIRED CANDIDATES ONLY)

★ Please check that this question paper contains 11 printed pages.

★ Q.P. Code given on the right hand side of the question paper should be written on the title page of the answer-book by the candidate.

★ Please check that this question paper contains 15 questions.

★ Please write down the serial number of the question in the answer-book before attempting it.

Time allowed : 2 hours Maximum Marks : 40

General Instructions :

Read the following instructions very carefully and strictly follow them :

(i) This question paper comprises 15 questions. All questions are compulsory.

(ii) This question paper is divided into three sections A, B and C.

(iii) Section A Questions No. 1 to 7 are short answer type questions. Each question carries 2 marks.

(iv) Section B Questions No. 8 to 13 are also short answer type questions. Each question carries 3 marks.

(v) Section C Questions No. 14 and 15 are case-based questions. Each question carries 4 marks.

(vi) Internal choices have been provided in some questions. Only one of the alternatives has to be attempted.

SECTION = A

1. What is a functional group ? Write the formula of functional group (a) alcohol, and (b) ketone. 2

2. (a) What are Dobereiner’s triads ? List three elements of such a triad. 2

(b) State Newland’s law of Octave . List two drawbacks of it. 2

3. (a) What is DNA ? “The DNA copies generated may be similar but may not be identical to the original”. Give reason to justify this statement. 2

(b) What is variation ? Why is variation beneficial to the species but not necessary for an individual ? 2

4. What happens when

(a) A spirogyra filament attains maturation ?

(b) Planaria is cut into any number of pieces ? 2

5. (a) What is the meaning of the following statement ? “In human beings, women have a perfect pair of sex chromosomes but men have a mismatched pair”.

(b) On the basis of above statement, how can you arrive at a conclusion that the mother is not responsible for the sex of a child ? Explain in brief. 2

6. (a) State Ohm’s law . A student has drawn V-I graph on the basis of his experimental observations. Why should this graph be a straight line passing through the origin ? 2

(b) When a 6·0 V battery is connected across a resistor there is a current of 30 mA in the circuit. Find the value of the resistance of the resistor in ohms. 2

7. Why do we say that the flow of energy in an ecosystem is unidirectional ? Explain with the help of a food chain having three trophic levels. 2

SECTION = B

8. (a) How is ozone formed at the higher levels of the atmosphere ? State how ozone performs the essential function at this level. In the 1980 s when it was noticed that the amount of ozone in the atmosphere is dropping sharply, what steps were taken to save the atmosphere ? 3

(b) What is Biological magnification ? How does it affect organisms present at various trophic levels, particularly the tertiary consumers ? 3

9. (a) What are structural isomers ? Draw the structure of two isomers of butane . Explain with the help of structure why we cannot have isomers of propane. 3

(b) What is a homologous series of carbon compounds ? Write the general formula of (i) alcohols, and (ii) aldehydes. Draw the structure of the first member of each series. 3

10. The atomic number of Calcium is 20. Answer the following questions stating the reason for each : 3

(a) Is Calcium a metal or a non-metal ?

(b) Is the atomic radii of calcium larger or smaller than

(i) potassium (atomic number 19), and (ii) iron (atomic number 26) ?

11. In one of his experiments with pea plants, Mendel observed that when tall pea plants (TT) were crossed with dwarf pea plants (tt), in the first generation (F1) plants only tall plants appeared.

(a) What happens to the traits for dwarfness in this case ?

(b) When the F1 generation plants were self-pollinated, he observed that in the plants of F2 generation both tall plants and dwarf plants were present. Explain briefly why it happened.

12. For a heater rated 4·4 kW; 220 V, calculate the following : 3

(a) The current

(b) The resistance of the heater

13. (a) (i) What is a magnetic needle ? Why does a magnetic needle get deflected when brought near a current carrying straight conductor ?

(ii) State right hand thumb rule. 3

(b) (i) The magnetic field in a region is represented by equidistant parallel lines. What do such lines indicate ?

(ii) Imagine that you are sitting in an examination room with your back to one wall. An electron beam moving horizontally from the back wall towards the front wall is deflected by a strong magnetic field to

your right side. What is the direction of the magnetic field ?

(iii) State the rule which you have applied in determining the direction of the magnetic field in this case. 3

SECTION = C

14. We are all aware of the term reproduction and we know that the continuity of life on our Earth from the origin to the present day has been possible only because of reproduction. Sexual reproduction is the most common mode of reproduction in flowering plants (angiosperms). Seeds are produced as a result of sexual reproduction. New plants are produced from these seeds only. In angiosperms, flower is the reproductive part of a plant. Most flowers have both male and female reproductive organs in them.

(a) Name the (i) male, and (ii) female part of a flowering plant. 1

(b) What happens to the zygote after fertilisation ? 1

(ii) Explain in brief, how fertilisation takes place in angiosperms. 2

15. A student wants to demonstrate a phenomenon of science in a science fair. He takes a straight solenoid fixed vertically on a wooden board and connects its two ends to a galvanometer. He also takes a strong bar magnet whose south pole is attached to a spring and suspends it with its axis vertical using a wooden stand in such a way that the north pole of the magnet is slightly above the upper end of the solenoid. He also ensures the free in and out movement of the north pole in the stationary solenoid . Now he pushes the magnet slightly downward and then releases it. The magnet starts oscillating. Based on your understanding, answer the following questions :

(a) What is observed in the galvanometer when the magnet oscillates and why ? 1

(b) What is observed in the galvanometer when the amplitude of oscillation is decreased to about one-half and why ? 1

(c) (i) State the type of movement shown by the needle of the galvanometer. What may be the reason for such a motion ? Write the conclusion which can be drawn from this activity. 2

(ii) Name and define the phenomenon demonstrated through this activity. Name the scientist who discovered this phenomenon. 2