CBSE Class 10 Science 2024 — Set 5

Questions in this 2024 Science paper (Set 5)

All 39 questions from this set, exactly as asked. Try each one, then open the question-paper PDF above for the complete paper.

1. 1.
   To balance the following chemical equation, the values of the coefficients x, y and z must be respectively: x Zn(NO₃)₂ → y ZnO + z NO₂ + O₂

   • (a) 4, 2, 2
   • (b) 4, 4, 2
   • (c) 2, 2, 4
   • (d) 2, 4, 2
2. 2.
   Which of the following is a redox reaction, but not a combination reaction?

   • (a) C + O₂ → CO₂
   • (b) 2 H₂ + O₂ → 2 H₂O
   • (c) 2 Mg + O₂ → 2 MgO
   • (d) Fe₂O₃ + 3 CO → 2 Fe + 3 CO₂
3. 3.
   The salt present in tooth enamel is:

   • (a) Calcium phosphate
   • (b) Magnesium phosphate
   • (c) Sodium phosphate
   • (d) Aluminium phosphate
4. 4.
   An aqueous solution of sodium chloride is prepared in distilled water. The pH of this solution is:

   • (a) 6
   • (b) 8
   • (c) 7
   • (d) 3
5. 5.
   A metal 'X' is used in thermit process. When 'X' is heated with oxygen, it gives an oxide 'Y', which is amphoteric in nature. 'X' and 'Y' respectively are:

   • (a) Mn, MnO₂
   • (b) Al, Al₂O₃
   • (c) Fe, Fe₂O₃
   • (d) Mg, MgO
6. 6.
   The process in which transport of soluble products of photosynthesis takes place in plants is known as:

   • (a) Transpiration
   • (b) Evaporation
   • (c) Conduction
   • (d) Translocation
7. 7.
   The correct sequence of events when someone's hand touches a hot object unconsciously:

   • (a) Receptors in skin → Motor neuron → Relay neuron → Sensory neuron → Effector muscle in arm
   • (b) Receptors in skin → Relay neuron → Sensory neuron → Motor neuron → Effector muscle in arm
   • (c) Receptors in skin → Sensory neuron → Relay neuron → Motor neuron → Effector muscle in arm
   • (d) Receptors in skin →…
8. 8.
   Sense organ in which olfactory receptors are present is:

   • (a) Nose
   • (b) Skin
   • (c) Tongue
   • (d) Inner ear
9. 9.
   The incorrect statement about placenta is:

   • (a) It is a disc embedded in the uterine wall.
   • (b) It contains villi on the embryo's side of the tissue.
   • (c) It has a very small surface area for glucose and oxygen to pass from mother to embryo.
   • (d) The embryo gets nutrition from the mother's blood through it.
10. 10.
    Select from the following the conditions responsible for the rapid spread of bread mould on a slice of bread:

    • (i) Formation of large number of spores
    • (ii) Presence of moisture and nutrients in bread
    • (iii) Low temperature
    • (iv) Presence of hyphae
    • (a) (i) and
    • (ii) (b)
    • (ii) and
    • (iv) (c)
    • (ii) and
    • (iii) (d)
    • (iii) and (iv)
11. 11.
    How will the image formed by a convex lens be affected, if the upper half of the lens is wrapped with a black paper?

    • (a) The size of the image formed will be one-half of the size of the image due to complete lens.
    • (b) The image of upper half of the object will not be formed.
    • (c) The brightness of the image will reduce.
    • (d) The lower half of the inverted image will not be formed.
12. 12.
    The phenomena of light involved in the formation of rainbow are:

    • (a) Refraction, reflection and dispersion
    • (b) Refraction, dispersion and internal reflection
    • (c) Reflection, dispersion and internal reflection
    • (d) Refraction, dispersion, scattering and total internal reflection
13. 13.
    The colour of light for which the refractive index of glass is minimum, is:

    • (a) Red
    • (b) Yellow
    • (c) Green
    • (d) Violet
14. 14.
    The current carrying device which produces a magnetic field similar to that of a bar magnet is:

    • (a) A straight conductor
    • (b) A circular loop
    • (c) A solenoid
    • (d) A circular coil
15. 15.
    A uniform magnetic field exists in the plane of paper as shown in the diagram. In this field, an electron (e⁻) and a positron (p⁺) enter as shown. The electron and positron experience forces: [Diagram shows uniform magnetic field with e⁻ and p⁺ entering]

    • (a) both pointing into the plane of the paper.
    • (b) both pointing out of the plane of the paper.
    • (c) pointing into the plane of the paper and…
16. 16.
    Which one of the following is not a natural ecosystem?

    • (a) Pond ecosystem
    • (b) Grassland ecosystem
    • (c) Forest ecosystem
    • (d) Cropland ecosystem
17. 17.
    Assertion (A): Some vegetable oils are healthy. Reason (R): Vegetable oils generally have long unsaturated carbon chains. Select the correct answer from the codes (A), (B), (C) and (D): (A) Both A and R are true and R is the correct explanation of A. (B) Both A and R are true, but R is not the correct explanation of A. (C) A is true, but R is false. (D) A is false, but R is true. (a) Both…
18. 18.
    Assertion (A): Sex of the children will be determined by what they inherit from their father. Reason (R): Women have XX sex chromosomes.

    • (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
    • (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
    • (c) Assertion (A) is true, but Reason (R)…
19. 19.
    Assertion (A): Electrons move from lower potential to higher potential in a conductor. Reason (R): A dry cell maintains electric potential difference across the ends of a conductor.

    • (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
    • (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion…
20. 20.
    Assertion (A): Ozone layer protects the surface of the Earth from harmful UV radiations. Reason (R): Chlorofluorocarbons (CFCs) are responsible for depletion of ozone layer.

    • (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
    • (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A). (c)…
21. 21 (a).
    Copper powder is taken in a china dish and heated over a burner. Name the product formed and state its colour. Write the chemical equation for the reaction involved.
22. 22.
    The melting and boiling points of carbon compounds are generally low and they are largely non-conductors of electricity. State two conclusions based on these two properties.
23. 23 (a).
    Sometimes while running, the athletes suffer from muscle cramps. Why? How is the respiration in this case different from aerobic respiration?
24. 24.
    Some unicellular organisms such as Plasmodium and Leishmania differ in the manner in which they reproduce. Name and explain the reproductive process taking place in them.
25. 25.
    The heat produced at a point due to concentration of sunlight by a convex lens burns a paper.

    • (a) Explain why it happens.
    • (b) Name the term (in the context of the lens used) given to the point at which the paper starts burning. What does the bright spot formed on the paper represent?
26. 26.
    An electric source can supply a charge of 500 coulomb. If the current drawn by a device is 25 mA, find the time in which the electric source will be discharged completely.
27. 27.
    Study the experimental set-up shown in the diagram and write the chemical equation for the chemical reaction involved. Name and define the type of reaction. List two other metals which can be used in place of iron to show the same type of reaction with copper sulphate solution. [Diagram shows: Stand, test tube with thread, copper sulphate solution, and iron nail]
28. 28.
    Name the ore of mercury and state the form in which it is found in nature. Write the chemical equations along with the conditions required for the reactions involved in the extraction of mercury from its ore.
29. 29.
    Taking the example of any two animal hormones along with their gland of secretion, explain how these hormones help

    • (i) in growth and development and
    • (ii) regulate metabolism, in the body.
30. 30.
    Mendel crossed pure tall pea plants (TT) with pure short pea plants (tt) and obtained F₁ progeny. When the plants of F₁ progeny were self-pollinated, plants of F₂ progeny were obtained.

    • (a) What did the plants of F₁ progeny look like? Give their gene combination.
    • (b) Why could the gene for shortness not be expressed in plants of F₁ progeny?
    • (c) Write the ratio of the plants obtained in F₂…
31. 31 (a).
    Study the diagram given below and answer the questions that follow: [Diagram shows an eye with converging lens and image formation indicating a defect]

    • (i) Name the defect of vision depicted in this diagram stating the part of the eye responsible for this condition.
    • (ii) List two causes of this defect.
    • (iii) Name the type of lens used to correct this defect and state its role in this case.
32. 32.
    What happens when a bundle of wires of soft iron is placed inside the coil of a solenoid carrying a steady current? Name the device obtained. Why is it called so? (b) Draw the magnetic field lines inside a current carrying solenoid. What does this pattern of magnetic field lines indicate?
33. 33.
    Differentiate between food chain and food web. In a food chain consisting of deer, grass and tiger, if the population of deer decreases, what will happen to the population of organisms belonging to the first and third trophic levels?
34. 34 (a).
    A few crystals of ferrous sulphate were taken in a dry boiling tube and heated. Tiny water droplets were observed in the tube after some time.

    • (i) From where did these water droplets appear? Explain.
    • (ii) What colour change will be observed during heating?
    • (iii) How many molecules of water are attached per molecule of FeSO₄ crystal? Write the molecular formula of crystalline forms of (I) Copper…
35. 35 (a).
    Design an experiment to demonstrate that carbon dioxide is essential for photosynthesis. Write the observation and conclusion of the experiment.
36. 36 (a).
    • (i) The potential difference across the two ends of a circuit component is decreased to one-third of its initial value, while its resistance remains constant. What change will be observed in the current flowing through it? Name and state the law which helps us to answer this question.
    • (ii) Draw a schematic diagram of a circuit consisting of a battery of four 1.5 V cells, a 5 Ω resistor, a 10 Ω…
37. 37 (a).
    Carbon is a versatile element that forms the basis of all living organisms and many of the things we use. A large variety of compounds of carbon are formed because of its tetravalency. Compounds of carbon are formed with oxygen, hydrogen, nitrogen, sulphur, chlorine and many other elements. (a) What are hydrocarbons?
38. 37 (b).
    List two properties by virtue of which carbon can form a large number of compounds that can be of varying chain or branched structure.
39. 37 (c)(i).
    (i) Write the formula of (1) aldehydes, and (2) ketones. Which of these is used in industries as a reactant for making bakelite, and write the chemical equation for the reaction that occurs between ethanoic acid and ethanol in the presence of a catalyst.
40. 38 (a).
    Pollination is an important process in sexual reproduction of plants. It is an essential process that facilitates fertilisation in plants. Pollinating agents can be wind, water, insects and birds. Several changes take place in the flower after the fertilization has taken place. (a) Write the main difference between self-pollination and cross-pollination.
41. 38 (b).
    Name the part of the flower which attracts insects for pollination. What happens to this part after fertilisation?
42. 38 (c)(i).
    (i) Define fertilisation. What is the fate of ovules and the ovary in a flower after fertilisation?
43. 39 (a).
    A highly polished surface such as a mirror reflects most of the light falling on it. In our daily life we use two types of mirrors — plane and spherical. The reflecting surface of a spherical mirrors may be curved inwards or outwards. In concave mirrors, reflection takes place from the inner surface, while in convex mirrors reflection takes place from the outer surface. (a) Define the principal…
44. 39 (b).
    A ray of light is incident on a concave mirror, parallel to its principal axis. If this ray after reflection from the mirror passes through a point at a distance of 10 cm from the pole of the mirror, find the radius of curvature of the mirror.
45. 39 (c)(i).
    (i) An object is placed at a distance of 10 cm from the pole of a convex mirror of focal length 15 cm. Find the position of the image.

Class 10 Science exam pattern (80 marks)

The theory paper carries 80 marks over 3 hours (39 questions, with internal choice in some). Section-wise structure:

Structure per the CBSE 2023-24 sample-paper design; question wording varies by set.

Prepare with

How to use these papers

1. 1Start chapter-wise early in the year — solve only the Science questions from a chapter you have just finished.
2. 2Switch to full timed papers 2–3 months before the exam: one complete set in the real time limit, no notes.
3. 3Self-mark against the marking scheme, then fix every mistake with our free NCERT solutions.
4. 4Re-attempt your weakest chapters until the recurring question types feel routine.

CBSE Class 10 Science 2024 paper — FAQ