CBSE Class 10 Science 2026 — Set 3

Questions in this 2026 Science paper (Set 3)

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.
   Pravin was given a list of characteristics associated with the process of anaerobic respiration in humans, in the table given below: Location —

   • (i) Muscle Cell; Condition —
   • (ii) Requires presence of Oxygen (O2) and Carbon dioxide (CO2); End Product —
   • (iii) 3-Carbon molecules. Which of the above characteristics is/are related to the above process?
   • (a) (i) and
   • (ii) (b)
   • (i) and
   • (iii) (c)
   • (ii) and…
2. 2.
   Observe the figure given below and identify the incorrect step for the activity set-up (destarching experiment with a watch-glass containing potassium hydroxide under a bell-jar):

   • (a) Both plants are kept in the dark room for three days before placing them in separate glass jars.
   • (b) Both plants are covered with separate wooden bell-jars.
   • (c) Use vaseline to seal the bottom of the jars with the…
3. 3.
   Walking in a straight line and riding a bicycle are activities which are possible due to coordination of which part of the brain?

   • (a) Fore-Brain / Cerebrum
   • (b) Mid-Brain / Cerebellum
   • (c) Hind-Brain / Cerebellum
   • (d) Hind-Brain / Medulla
4. 4.
   In a synapse, the chemical signal is transmitted from:

   • (a) Dendritic end of one neuron to axonal end of another neuron.
   • (b) Axon to cell body of the same neuron.
   • (c) Cell body to axonal end of the same neuron.
   • (d) Axonal end of one neuron to dendritic end of another neuron.
5. 5.
   Organisms of a higher trophic level which feed on several types of organisms belonging to a lower trophic level form the:

   • (a) Food web
   • (b) Ecosystem
   • (c) Ecological pyramid
   • (d) Food chain
6. 6.
   In accumulation of toxic substances at higher trophic levels of an ecosystem through the food chain, which of the following organisms is affected the most?

   • (a) Small aquatic plants
   • (b) Human beings
   • (c) Small fish
   • (d) Large fish
7. 7.
   The growth of tendrils in grapes plants is due to:

   • (a) Effect of light
   • (b) Effect of gravity
   • (c) Rapid cell division in tendril cells in contact with the support
   • (d) Rapid cell division in tendril cells that are away from the support
8. 8.
   Assertion (A): Natural replenishment of soil will not take place in absence of microbes. Reason (R): Microbes, comprising of bacteria and fungi, break down dead remains and waste products of organisms, and they go into the soil. Select the correct answer from the codes given below.

   • (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
   • (b) Both…
9. 9.
   Assertion (A): The basic filtration unit in the kidneys, like in the lungs, is a cluster of very thin-walled blood capillaries. Reason (R): Each capillary cluster in the kidney is associated with the cup-shaped end of a coiled tube called Bowman's capsule. Select the correct answer from the codes given below. (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct…
10. 10.
    Chlorofluorocarbons (CFCs) have been linked to depletion of ozone layer. In 1987, the United Nations Environment Programme (UNEP) succeeded in making an agreement. State this agreement. (ii) What is the role of ozone in our atmosphere?
11. 11.
    What kind of respiration provides more energy and why?
12. 12.
    Separation of right side and left side of the heart is useful to keep oxygenated and deoxygenated blood from mixing. Various organisms have different types of heart. (I) Fill in the blanks

    • (i) to
    • (iii) correctly according to the type of organisms and their evolution in terms of blood circulation: Fish —
    • (i) ____ chambers, Mixed blood, Single circulation;
    • (ii) ____ — 3-chambered, Mixed blood…
13. 13.
    In xylem tissue, vessels and tracheids of the roots, stems and leaves are interconnected to form a continuous system of water-conducting channels reaching all parts of the plant. Explain how this is achieved.
14. 14.
    Show the cross and observations made by Mendel when he crossed pure tall pea plant with a pure short pea plant to get F1 progeny.
15. 15.
    Read the passage: Not all plants carry out photosynthesis by the same mechanism. In most plants it depends directly on gaseous carbon dioxide that diffuses into the leaf. However, some plants can store carbon dioxide in the vacuole of the leaf cells as part of a complex carbon compound, which is transported to the chloroplast and releases carbon dioxide when required for photosynthesis. This…
16. 16.
    Attempt (a): Observe the given diagram (showing budding) and answer:

    • (i) Give the name of the structure and type of reproduction shown in the above diagram.
    • (ii) State one advantage and one disadvantage of the above mentioned method of reproduction.
    • (iii) Give reason: Asexual reproduction lacks genetic variation.
    • (iv) Why have higher organisms resorted to sexual reproduction in spite of its…
17. 17.
    Which of the following is an example of a displacement reaction?

    • (a) The combustion of natural gas
    • (b) The reaction of a reactive metal with dilute acid
    • (c) The electrolysis of water
    • (d) The reaction of quick lime with water
18. 18.
    To a small amount of copper oxide in a beaker, when we add dilute hydrochloric acid slowly with stirring, the change in the colour of the solution is due to the formation of:

    • (a) Copper(II) oxide, which is black in colour.
    • (b) Copper(I) chloride, which is blue in colour.
    • (c) Copper(II) chloride, which is blue-green in colour.
    • (d) Copper(I) oxide, which is black in colour.
19. 19.
    In the following equation, x KI + H2O2 → I2 + y KOH, x and y respectively are:

    • (a) 2, 2
    • (b) 1, 2
    • (c) 2, 1
    • (d) 1, 1
20. 20.
    Consider the structures 'X' (a straight-chain butane, CH3–CH2–CH2–CH3) and 'Y' (a branched isobutane / 2-methylpropane). Which of the following statements are correct?

    • (i) 'X' and 'Y' are homologues.
    • (ii) 'X' and 'Y' have the same structural formula, but different molecular formula.
    • (iii) 'X' and 'Y' have the same molecular formula, but different structural formula.
    • (iv) 'X' and 'Y' are…
21. 21.
    The reaction of calcium with cold water is:

    • (a) Less violent, but the heat evolved is sufficient for the hydrogen to catch fire.
    • (b) Very violent and exothermic and hydrogen catches fire.
    • (c) Exothermic, but the heat evolved is not sufficient for the hydrogen to catch fire.
    • (d) Slow and endothermic.
22. 22.
    In which case/cases will the bulb glow (from a figure showing electrical circuits/cases i, ii, iii testing conductivity), considering that all other connections of electric circuit are complete and working?

    • (a) Case
    • (i) only
    • (b) Case
    • (ii) only
    • (c) Cases
    • (ii) and
    • (iii) (d) Case
    • (iii) only
23. 23.
    When zinc reacts with NaOH, the product formed is:

    • (a) Na2O
    • (b) ZnO
    • (c) Na2ZnO2
    • (d) Zn(OH)2
24. 24.
    Assertion (A): There are large number of compounds with many carbon atoms linked to each other. Reason (R): Carbon-Carbon bond is very strong and stable. Select the correct answer from the codes given below.

    • (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…
25. 25.
    Show the formation of the following ionic compounds by transfer of electrons between the combining atoms:

    • (i) Sodium oxide (Na2O);
    • (ii) Magnesium chloride (MgCl2). (Given: Atomic number: Na = 11, Mg = 12, O = 8, Cl = 17)
26. 26.
    2 g of green coloured crystals of ferrous sulphate are heated in a dry boiling tube. Name the type of chemical reaction taking place. Write the balanced chemical equation for the reaction. Is this an exothermic or an endothermic reaction?
27. 27.
    Attempt (a): Give reasons:

    • (i) For dilution of an acid, acid is added into water and not water into acid.
    • (ii) Dry HCl gas does not turn blue litmus red whereas dilute hydrochloric acid does.
    • (iii) Blue colour of Copper(II) sulphate crystals turns white on heating.
28. 28 (a).
    Read the passage: An electrochemical process is used for refining metals by selectively dissolving and depositing them through electrolysis. Electrolytic refining is used for metals like Copper, Zinc, Tin, Nickel, Silver and Gold. (a) Define anode mud.
29. 28 (b).
    In electrolytic refining of copper, name the anode and the cathode.
30. 28 (c).
    (c)(i) With the help of chemical equations, show the extraction of copper from its ore Cu2S.
31. 29.
    Attempt (a):

    • (i) What is homologous series? Which two of the following organic compounds belong to the same homologous series? C2H4, C4H10, C3H4, C4H8.
    • (ii) Write the product(s) in the following reactions: (I) CH3–CH2–OH + CH3COOH (Acid) →; (II) C2H5OH + O2 (Burning) →.
    • (iii) Why does micelle formation take place when soap is added to water?
32. 30.
    The correct way to connect an ammeter and a voltmeter in an electric circuit is:

    • (a) Ammeter in parallel and voltmeter in series
    • (b) Ammeter and voltmeter both in parallel
    • (c) Ammeter in series and voltmeter in parallel
    • (d) Ammeter and voltmeter both in series
33. 31.
    Observe the given ray diagram showing refraction (dispersion) through a prism and choose the correct option for colour of rays 1 and 2 (ray 1 is deviated least, ray 2 is deviated most):

    • (a) Blue (ray 1), Red (ray 2)
    • (b) Green (ray 1), Yellow (ray 2)
    • (c) Red (ray 1), Violet (ray 2)
    • (d) Violet (ray 1), Red (ray 2)
34. 32.
    Assertion (A): The needle of a compass, kept in an external magnetic field, always aligns itself in the North-South direction of the Earth. Reason (R): The behaviour of the needle of the compass is similar to the behaviour of a freely suspended bar magnet. Select the correct answer from the codes given below. (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct…
35. 33.
    A ray of light enters into medium B from medium A as shown in the given figure (the ray bends towards the normal on entering B).

    • (a) Which one of these two media is optically denser than the other medium? Justify your answer.
    • (b) If the speed of light in medium A is VA and in medium B is VB, then what is the refractive index of medium B with respect to medium A?
36. 34.
    Attempt (a): What happens when light is scattered from

    • (i) very fine particles and
    • (ii) very large size particles of medium? Justify your answer in each case.
37. 35 (a).
    Study the given diagram (of a defective eye) and answer: (a) Write the name of the eye defect shown in the diagram. Where is the image formed in this eye defect with respect to the retina of the eye?
38. 35 (b).
    List two causes of this eye defect (myopia).
39. 35 (c).
    With the help of a diagram, show how this eye defect of vision (myopia) is corrected.
40. 36.
    Name a device which is used to:

    • (i) Maintain a constant potential difference in a circuit.
    • (ii) Change the electric current in an electric circuit.
    • (b) When the potential difference between the terminals of an electric heater is 110 V, a current of 5 A flows through it. What will be the value of current flowing through it when the potential difference is increased to 220 V?
41. 37.
    Consider the given electric circuit. Calculate the following:

    • (a) Total resistance of the circuit;
    • (b) The electric current drawn from the battery;
    • (c) Potential difference between points P and Q.
42. 38.
    The variation of image distance (v) with the object distance (u) for a convex lens is given in the observation table: S.No 1: u = -150, v = +30; 2: u = -75, v = +37.5; 3: u = -50, v = +50; 4: u = -37.5, v = +75; 5: u = -30, v = +150; 6: u = -15, v = +37.5 (all in cm). Analyse it and answer: (a) Without calculation, find out the focal length of the given convex lens. Justify your answer. (b)…
43. 39.
    Attempt (a):

    • (i) What is a solenoid? Draw a diagram showing the magnetic field pattern due to a current-carrying solenoid (inside and outside).
    • (ii) Name any two factors on which the magnitude of the magnetic field due to a current-carrying solenoid depends.
    • (iii) A current-carrying solenoid is stretched and converted into a straight wire carrying current. Draw a diagram showing the magnetic…

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 2026 paper — FAQ