CBSE Class 10 Science 2025 — Set 6

Questions in this 2025 Science paper (Set 6)

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.
   In the following experimental setup of electrolysis of water, if P and Q are the gases collected in the test tubes enclosing the electrodes R and S, then select the option/options in which the matching is correct:

   • (i) P - Oxygen gas, R - Anode
   • (ii) P - Hydrogen gas, R - Cathode
   • (iii) Q - Hydrogen gas, S - Cathode
   • (iv) Q - Oxygen gas, S - Anode
   • (a) (i) and
   • (ii) (b)
   • (iii) and
   • (iv) (c)
   • (i) and…
2. 2.
   You have three aqueous solutions A, B and C as given below: A - Potassium nitrate B - Ammonium chloride C - Sodium carbonate The ascending order of the pH of these solutions is:

   • (a) A < B < C
   • (b) B < C < A
   • (c) C < A < B
   • (d) B < A < C
3. 3.
   Select from the following a statement which is not true about burning of magnesium ribbon in air:

   • (a) It burns with a dazzling white flame.
   • (b) A white powder is formed on burning.
   • (c) It is an endothermic reaction.
   • (d) It is an example of a combination reaction.
4. 4.
   A hydrocarbon which does not belong to the same homologous series of carbon compounds is:

   • (a) C4H10
   • (b) C6H14
   • (c) C7H14
   • (d) C10H22
5. 5.
   The colour of the solution observed after about 1 hour of placing iron nails in copper sulphate solution is:

   • (a) Blue
   • (b) Pale green
   • (c) Yellow
   • (d) Reddish brown
6. 6.
   Juice of tamarind turns blue litmus to red. It is because of the presence of a chemical compound called:

   • (a) Acetic acid
   • (b) Methanoic acid
   • (c) Oxalic acid
   • (d) Tartaric acid
7. 7.
   The water of crystallisation is present in:

   • (i) Bleaching Powder
   • (ii) Plaster of Paris
   • (iii) Washing Soda
   • (iv) Baking Soda
   • (a) (ii) and
   • (iv) (b)
   • (ii) and
   • (iii) (c)
   • (i) and
   • (iii) (d)
   • (i) and (iv)
8. 8.
   A tall pea plant with round seeds (TTRR) is crossed with a short pea plant with wrinkled seeds (ttrr). The F1 generation will be:

   • (a) 25% tall with round seeds
   • (b) 50% tall with wrinkled seeds
   • (c) 75% tall with wrinkled seeds
   • (d) 100% tall with round seeds
9. 9.
   A pair of endocrine glands located in the human brain is:

   • (a) Parathyroid and Pituitary
   • (b) Pineal and Thymus
   • (c) Hypothalamus and Thymus
   • (d) Hypothalamus and Pineal
10. 10.
    Select the option having correct matching of the organism given in Column I with the mode of reproduction in Column II: Column I: P - Leishmania, Q - Spirogyra, R - Planaria, S - Plasmodium Column II: 1 - Regeneration, 2 - Multiple Fission, 3 - Binary Fission, 4 - Fragmentation, 5 - Budding

    • (a) P-4, Q-2, R-1, S-3
    • (b) P-3, Q-4, R-5, S-2
    • (c) P-3, Q-4, R-1, S-2
    • (d) P-4, Q-3, R-2, S-1
11. 11.
    The basic filtration unit of the excretory system in human beings is:

    • (a) Nephron
    • (b) Urethra
    • (c) Neuron
    • (d) Urinary bladder
12. 12.
    In human alimentary canal, the digestive juice secreted by the gastric glands are:

    • (a) Bile, Trypsin, Pepsin
    • (b) Hydrochloric acid, Pepsin, Mucus
    • (c) Lipase, Bile, Mucus
    • (d) Salivary amylase, Pepsin, Bile
13. 13.
    Identify from the following the ray diagram which shows the correct path of the reflected ray for the ray incident on a concave mirror as shown (a ray parallel to the principal axis passing beyond C towards P):

    • (a) Ray reflects passing through F between C and F
    • (b) Ray reflects and passes through C then diverges
    • (c) Ray reflects passing through F
    • (d) Ray reflects parallel to principal axis
14. 14.
    The part of human eye which controls the amount of light entering into it:

    • (a) Iris
    • (b) Cornea
    • (c) Ciliary muscles
    • (d) Pupil
15. 15.
    Consider the following food chain: Grass -> Grasshopper -> Frog -> Snake -> Eagle If the amount of energy available at third trophic level is 50 kJ, the available energy at the producer level was:

    • (a) 0.5 kJ
    • (b) 5 kJ
    • (c) 500 kJ
    • (d) 5000 kJ
16. 16.
    The incorrect statement about ozone is:

    • (a) It is a deadly poisonous gas.
    • (b) It shields the surface of the earth from UV radiation from sun.
    • (c) It is used as a refrigerant and in fire-extinguishers.
    • (d) It is formed by combining oxygen molecule and free oxygen atom.
17. 17.
    Assertion (A): Carbon and its compounds are our major sources of fuels. Reason (R): Most of the carbon compounds on burning release a large amount of heat and light.

    • (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
    • (b) Both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of the Assertion (A). (c)…
18. 18.
    Assertion (A): Xylem tissue moves water and minerals obtained from the soil by the roots. Reason (R): Xylem tissue is found only in the roots of a plant.

    • (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
    • (b) Both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of the Assertion (A).
    • (c) Assertion (A)…
19. 19.
    Assertion (A): In the common domestic circuits the earth wire is connected to a metallic plate buried deep inside the earth. Reason (R): Earth wire ensures that any leakage of current to the metallic body of the appliance keeps its potential to that of the earth, so the user may not get a severe electric shock. (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct…
20. 20.
    Assertion (A): Food web is a network of several food chains operating in an ecosystem. Reason (R): Food web decreases the stability of an ecosystem.

    • (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
    • (b) Both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of the Assertion (A).
    • (c) Assertion (A) is…
21. 21.
    A light green coloured solution of sulphate salt of metal 'P' is taken in a beaker, a rod of another metal 'Q' is put in this solution as shown in the following figure. After about 1 hour the light green solution becomes colourless. Identify the metals 'P' and 'Q' and write the chemical equation for the reaction that occurs. State the conclusion of this reaction in terms of reactivity series of…
22. 22.
    How is brain protected in our body? (b) A doctor finds in one of his patients that he is not maintaining a proper posture and balance of his body. State the region of brain and also the part of brain which is responsible for it.
23. 23.
    "Proteins control the expression of various characters." Explain this statement by taking an example of "tallness" as a characteristic in plants.
24. 24.
    Study the figure in which the path of a ray of light going from Medium 1 to Medium 2 is shown (the ray bends away from the normal as it enters Medium 2).

    • (a) Out of the two Media - Medium 1 and Medium 2, in which is the speed of light more?
    • (b) State reason of bending of the refracted ray away from the normal.
    • (c) Express refractive index of Medium 2 with respect to Medium 1 in terms of speed of…
25. 25.
    Give reasons:

    • (i) The sky appears dark to passengers flying at very high altitude.
    • (ii) 'Danger' signal lights are red in colour.
26. 26.
    We do not clean natural ponds or lakes whereas an aquarium or a swimming pool needs to be cleaned regularly. Why?
27. 27.
    Write balanced chemical equations for the reactions that occur when:

    • (a) steam is passed over red hot iron.
    • (b) natural gas is burnt in air.
    • (c) glucose reacts with oxygen in the cells of our body and provides energy.
28. 28.
    State the chemical property in each case on which the following uses of baking soda are based upon:

    • (i) as an anti-acid
    • (ii) as a constituent in making baking powder
    • (iii) in soda-acid fire-extinguishers
29. 29.
    Name the blood vessel that brings

    • (i) oxygenated blood
    • (ii) deoxygenated blood, to the human heart. Also name that chamber of the heart which receives deoxygenated blood and state how deoxygenated blood from this chamber is sent to lungs for oxygenation.
30. 30.
    The gene combination of purple flowered pea plants is denoted as (WW) and that of white flowered pea plants as (ww). When these two plants are crossed F1 generation is obtained.

    • (a) List two observations made by Mendel in F1 generation plants.
    • (b) Give the
    • (i) percentage of white flowered plants and
    • (ii) ratio of the gene combinations WW, Ww and ww in F2 generation.
    • (c) Write one difference…
31. 31.
    A student placed a candle flame at different distances from a convex lens and focused its image on a screen. He recorded his observation in tabular form as given below: S.No. | Distance of flame from the lens (cm) | Distance of the image from the lens 1 | -90 | +18 2 | -60 | +20 3 | -40 | +24 4 | -30 | +30 5 | -24 | +40 6 | -20 | +60 7 | -18 | +90 8 | -12 | +120 Analyse the observation table and…
32. 32.
    A person uses lenses of +2.0 D power in his spectacles for the correction of his vision.

    • (a) Name the defect of vision the person is suffering from.
    • (b) List two causes of this defect.
    • (c) Determine the focal length of the lenses used in the spectacles.
33. 33.
    Explain the statement "Potential difference between two points is 1 volt". (b) What do the symbols given below represent in an electric circuit? Write one function of each. (i) A circle with A inside and + and - terminals (ammeter symbol) (ii) A zigzag line with an arrow (variable resistor/rheostat symbol)
34. 34.
    Name an alcohol and a carboxylic acid having two carbon atoms in their structures. Draw their structures and state how this alcohol can be converted into a carboxylic acid. What happens when these two compounds react in the presence of an acid? Write chemical equations for the reactions involved in the two cases mentioned above. (b) What are soaps? Write the structure of a soap molecule. Explain…
35. 35.
    Define Puberty. List any two changes seen in boys at the time of puberty. (b) Why are testes in human males located outside the abdominal cavity in scrotum? (c) List any three techniques of contraception used by humans. Which one of these is not meant for males?
36. 36.
    What are magnetic field lines? How is the direction of magnetic field at a point determined? Draw the pattern of magnetic field lines produced by a current carrying circular loop. Mark on it the direction of

    • (i) current and
    • (ii) magnetic field lines. Name the two factors on which the magnitude of the magnetic field due to a current carrying coil depends.
37. 37.
    Many pure metals like copper, iron and gold are very soft and as such are considered unsuitable for certain uses. Metallic objects around us such as cooking utensils, statues, ornaments, guns etc. are actually not made up of pure metals. Instead of pure metals, alloys are used in the design of most of the useful objects. Making alloys enhances the basic properties of a metal which is the primary…
38. 37 (a).
    (Case Study Q37-I) How does electrical conductivity and melting point of a metal change when it is converted to its alloy by mixing a small amount of an element in it?
39. 37 (b).
    (Case Study Q37-II) Name an alloy used for welding two wires together in an electric circuit. Write its major constituents.
40. 37 (c).
    (Case Study Q37-III) (a) What are alloys? How is 'Brass' (an alloy) prepared?
41. 38.
    The growth movements of plant parts in which the direction of the stimulus determines the direction of the response is known as tropic movements or tropism. Plants also have non-directional movements which may not be growth dependent.
42. 38 (a).
    (Case Study Q38-I) Name the movement which causes 'X' to grow downwards and 'Y' to grow upwards respectively. (Refer above figure showing a plant with roots growing down and shoot growing up)
43. 38 (b).
    (Case Study Q38-II) Write the name of a hormone that plays a major role in

    • (i) falling of leaves
    • (ii) rapid cell division.
44. 38 (c).
    (Case Study Q38-III) (a) Leaves of the sensitive plant move very quickly in response to 'touch'. How is this stimulus of touch communicated and explain how the movement takes place.
45. 39.
    Study the circuit shown in which two resistors X and Y of resistances 3 ohm and 6 ohm respectively are joined in series with a battery of 2 V. A voltmeter is connected across the combination and an ammeter is in series.
46. 39 (a).
    (Case Study Q39-I) Draw a circuit diagram showing the above two resistors X and Y joined in parallel with same battery and same ammeter and voltmeter.
47. 39 (b).
    (Case Study Q39-II) In which combination of resistors will the

    • (i) potential difference across X and Y and
    • (ii) current through X and Y, be the same?
48. 39 (c).
    (Case Study Q39-III) (a) Find the current drawn from the battery by the series combination of the two resistors (X and Y).

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 2025 paper — FAQ