CBSE Class 10 Science 2026 — Set 5

Questions in this 2026 Science paper (Set 5)

All 43 questions from this set, exactly as asked. Try each one, then open the question-paper PDF above for the complete paper.

1. 1.
   Identify the part that controls the closing and opening of the stomatal pore in leaves of plants. Select the correct option.

   • (a) Stomata
   • (b) Epidermal cells
   • (c) Guard cells
   • (d) Chloroplasts
2. 2.
   Identify the endocrine gland that regulates the growth of human body.

   • (a) Pituitary gland
   • (b) Thyroid gland
   • (c) Pancreas
   • (d) Adrenal gland
3. 3.
   Choose the equation of reaction that correctly represents anaerobic respiration in muscles :

   • (a) Glucose → Pyruvate → Ethanol + CO2 + Energy (in absence of O2)
   • (b) Glucose → Pyruvate → Energy (in presence of O2)
   • (c) Glucose → Pyruvate → Ethanol + Energy (in lack of oxygen)
   • (d) Glucose → Pyruvate → Lactic acid + Energy (in lack of oxygen)
4. 4.
   In human beings, the implantation of fertilised egg takes place in which part of female reproductive system ?

   • (a) Oviduct
   • (b) Cervix
   • (c) Uterus
   • (d) Vagina
5. 5.
   When a human egg is fertilized by a sperm having 'Y' chromosome, the zygote has the following combination of chromosomes :

   • (a) 44 + XX
   • (b) 22 + XX
   • (c) 44 + XY
   • (d) 22 + XY
6. 6.
   Which of the following is a non-biodegradable pollutant ?

   • (a) Paper
   • (b) DDT
   • (c) Wood
   • (d) Vegetable peel
7. 7.
   In an ecosystem, the decomposers perform an important role. Select the option indicating the role of decomposers.

   • (a) Convert inorganic materials to simpler forms
   • (b) Break down complex organic substances to simple inorganic substances.
   • (c) Break down inorganic substances into organic substances.
   • (d) Do not act on organic compounds.
8. 8.
   Assertion (A) : Bacteria that can withstand heat have better chances of survival in a heat wave. Reason (R) : Accumulation of variations in a species increases the chances of its survival in changing environment. Select the appropriate option: (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…
9. 9.
   Assertion (A) : The peristaltic movements occur all along the gut. Reason (R) : The lining of the gut has muscles that contract rhythmically to push the food in regulated manner. Select the appropriate option: (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, but Reason (R) is not the…
10. 10.
    Give a diagrammatic representation of nutrition in Amoeba.
11. 11.
    Observe the given figure and identify the labelled parts P, Q, R and S :
12. 12.
    Briefly mention the steps in double-circulation through human heart.
13. 13.
    Based on Mendel's experiment show the cross between round, yellow seeds of pea plant (RRYY) with wrinkled and green seeds of pea plant (rryy) upto F2 generation. Write the number of seeds/plants with following genetic (Genotype) makeup in F2 generation :

    • (i) RRYY
    • (ii) rryy
14. 14.
    Mention any one harmful effect of using plastic bags on the environment. Suggest better alternatives to the usage of plastic bags. (b) Paddy fields require a large amount of water. The pesticides and chemical fertilizers used are washed down into the soil or waterbodies. How do these chemicals reach our bodies ? What is this phenomenon known as ?
15. 15.
    Kidneys help to regulate the volume of fluid and various metabolites waste products in the body. Normally, kidney filter about 180 L of fluid daily but the volume actually excreted out is only a litre or two a day. Patients with kidney failures can be saved by dialysis and kidney transplant. (a) Write the structure and function of Bowman's capsule.
16. 16.
    Although kidneys filter a large amount (about 180 L daily) of fluids, still the excretion from the body is only about a litre or two. Why ?
17. 17.
    What is excretion ? Why is it necessary for any living organism ?
18. 18.
    • (i) In an angiospermic flower, fertilization is said to take place when male gametes carried in the pollen tube fuse with the female gamete, present in the embryo sac. This results in lot of changes in different parts of the flower. State the changes taking place in the following structures of flower post fertilization :
    • (a) Zygote
    • (b) Ovule
    • (c) Ovary
    • (d) Sepals
    • (ii) Define germination.
19. 19.
    The volume ratio of hydrogen and oxygen gases liberated during electrolysis of water is :

    • (a) 1 : 2
    • (b) 2 : 1
    • (c) 1 : 3
    • (d) 4 : 1
20. 20.
    Which of the following set of compounds does not belong to same homologous series ?

    • (a) CH4 and C4H10
    • (b) C2H6 and C3H8
    • (c) C3H8 and C5H12
    • (d) C4H8 and C5H12
21. 21.
    Which of the following is an amphoteric oxide ?

    • (a) Na2O
    • (b) K2O
    • (c) CO2
    • (d) Al2O3
22. 22.
    Study the following table and select the correct option : Salt | Acid used | Base used | Nature of Salt

    • (a) NaCl | HCl | NaOH | Basic
    • (b) Na2CO3 | H2CO3 | NaOH | Neutral
    • (c) Na2SO4 | H2SO4 | NaOH | Acidic
    • (d) CH3COONa | CH3COOH | NaOH | Basic
23. 23.
    Which of the following will not undergo addition reaction ?

    • (a) C4H8
    • (b) C2H2
    • (c) C3H8
    • (d) C2H4
24. 24.
    Four solutions, namely fructose, ethanol, hydrochloric acid and sodium hydroxide filled in four separate beakers are connected one by one in an electric circuit with a bulb. The solutions in which the bulb will glow when current is passed are :

    • (a) ethanol and hydrochloric acid
    • (b) fructose and ethanol
    • (c) fructose and sodium hydroxide
    • (d) hydrochloric acid and sodium hydroxide
25. 25.
    Which gas is evolved when magnesium metal reacts with very dilute HNO3 ?

    • (a) Oxygen
    • (b) Nitrogen
    • (c) Hydrogen
    • (d) Nitrogen Dioxide
26. 26.
    In the question two statements are given – one labelled as Assertion (A) and other labelled as Reason (R). Answer this question selecting the appropriate option from (A), (B), (C) and (D) given below : Assertion (A) : Reaction of quick lime with water is an exothermic reaction. Reason (R) : A large amount of heat is evolved on the reaction of quick lime and water. (A) Both Assertion (A) and…
27. 27.
    Define the following terms :

    • (i) Olfactory indicator
    • (ii) Water of crystallization
28. 28.
    What happens when

    • (i) lead (II) nitrate is heated ?
    • (ii) iron (II) sulphate is heated ?
    • (iii) silver chloride is exposed to sunlight ? Write balanced chemical equations of the reactions involved in support of your answer.
29. 29.
    • (a) Give the chemical name and formula of Plaster of Paris.
    • (b) Write the chemical equation of its preparation.
    • (c) Give any two uses of it.
30. 30.
    Alcohol forms a homologous series with general formula CnH2n+1–OH and –OH group as functional group. Ethanol is commonly called alcohol and is used in alcoholic drinks. It is good solvent, used in medicines, cough syrups, tonics etc.

    • (a) Write structural formula and name of 4th member of alcohol homologous series.
    • (b) What happens when ethanol is heated with alkaline KMnO4 ? Write chemical…
31. 31.
    • (i) Give reasons for the following : (I) Ionic compound have generally high melting points and boiling points. (II) Solder, an alloy of lead and tin, is used for welding electrical wires. (III) Carbon cannot reduce the oxides of Na or Mg.
    • (ii) The reaction of compound 'X' with aluminium is used to join railway tracks : (I) Identify the compound 'X'. (II) Name the reaction. (III) Write the…
32. 32.
    Rays from the sun converge at a point 25 cm behind a convex lens. The distance at which an object be placed in front of the lens to get a virtual image, is :

    • (a) 20 cm
    • (b) 40 cm
    • (c) 50 cm
    • (d) More than 50 cm
33. 33.
    To restore clear vision in persons whose size of the eye ball has reduced, he/she is suggested to use suitable

    • (a) Converging lens
    • (b) Diverging lens
    • (c) Bifocal lens
    • (d) Cylindrical lens
34. 34.
    Assertion (A) : The needle of a magnetic compass kept in strong external magnetic field, always aligns itself in north-south direction on the earth. Reason (R) : Behaviour of the needle of a compass is same as that of a freely suspended bar magnet. (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)…
35. 35.
    Relate the speed of light in the given medium with its optical density. (b) Using the information given in the table below, arrange the medium A, B and C in the ascending order of their optical density. Medium | Speed of light (m/s) A | 2.25 × 10⁸ B | 2 × 10⁸ C | 2.08 × 10⁸
36. 36.
    • (i) How does the change in curvature of the eye lens helps us in the process of seeing the nearby objects clearly ?
    • (ii) State the range of the power of accommodation of a normal human eye.
37. 37.
    Draw the ray diagram for refraction of light through a glass prism and mark angle of refraction and angle of deviation. (b) When the path of a light ray refracted through a glass prism is reversed how will the angle of deviation change ? Explain.
38. 38.
    A ray of light after reflection from a concave mirror becomes parallel to its principal axis. Draw a labelled ray diagram to show this. (b) (i) Differentiate between the virtual images formed by a convex mirror and concave mirror. (ii) "The value of magnification 'm' for a mirror is –2." Calculate the height of object if the height of image is 20 cm.
39. 39.
    Why does an electric bulb become dim when an electric heater in parallel circuit is switched ON ? (b) How to connect three resistors each of resistance 8 Ω, so that the equivalent resistance of the combination is 12 Ω ? Draw diagram of the combination and justify your answer.
40. 40.
    Three students Shweta, Ayesha and Samridhi were performing an experiment to understand the factors on which the resistance of a conductor depends. Each one of them completed electric circuit with the help of a cell, an ammeter, a plug key and wire. Shweta put nichrome wire of length 'l' in the circuit and after plugging the key, noted current in the ammeter. Ayesha put nichrome wire of same…
41. 41.
    What happens to the ammeter reading if the area of cross-section of nichrome wire is doubled, keeping the length of wire 'l' the same ?
42. 42.
    Define 'resistivity'. Write its SI unit. Compare the resistivity of an alloy with its constituents metals.
43. 43.
    • (i) Draw a diagram showing the magnetic field lines around a bar magnet. Write any two characteristics of magnetic field lines.
    • (ii) Write the statement of Right hand thumb rule.
    • (iii) The concentric circles representing the magnetic field around a current carrying straight wire become larger and larger as we move away from the wire. How does magnetic field change on these concentric circles ?

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