PYQ Vault

Day 11: CBSE Class 10 Science

5 questions. Try each one first, then open its answer.

  1. Question 1

    The Human Eye and the Colourful World. Asked 3 times: 2023*, 2025*, 2026 (* = numbers or wording changed that year)

    37
    (a) What is Tyndall effect ? (b) What happens when sunlight is scattered from the particles of very large size ? (c) ‘Danger’ signals are always red in colour. Why ?

  2. Question 2

    Carbon and its Compounds. Asked 3 times: 2022*, 2023*, 2025 (* = numbers or wording changed that year)

    7
    If we make carbon skeleton with four carbon atoms, the two different possible skeletons will be

    Tap an option to check your answer.

  3. Question 3

    Carbon and its Compounds. Asked 3 times: 2023*, 2024*, 2025 (* = numbers or wording changed that year)

    34 (b)
    What are soaps ? Write the structure of a soap molecule. Explain the cleansing action of a soap. Why are soaps not considered suitable for washing clothes in a region where water is hard ? How is this problem overcomed ?

  4. Question 4

    Chemical Reactions and Equations. Asked 3 times: 2023*, 2024*, 2025 (* = numbers or wording changed that year)

    5
    The values of a, b, c and d in the following balanced chemical equation are respectively : a Pb(NO3)2→heatb PbO+c NO2+d O2\mathbf{a}\,\mathrm{Pb(NO_3)_2} \xrightarrow{\text{heat}} \mathbf{b}\,\mathrm{PbO} + \mathbf{c}\,\mathrm{NO_2} + \mathbf{d}\,\mathrm{O_2}

    Tap an option to check your answer.

  5. Question 5

    Control and Coordination. Asked 3 times: 2023*, 2024*, 2025 (* = numbers or wording changed that year)

    9
    The plant hormone whose concentration stimulates the cells to grow longer on the side of the shoot which is away from light is :

    Tap an option to check your answer.