PYQ Vault

Day 133: CBSE Class 10 Science

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

  1. Question 1

    Chemical Reactions and Equations. Asked once: 2024 (same type asked 3 times)

    27
    Answer the following questions in the context of electrolysis of water : (a) Why is this reaction/process called a decomposition reaction ? (b) Giving reason state whether this reaction is exothermic or endothermic. (c) Name the gases collected at the anode and cathode. (d) What is the mass ratio of the gases collected at the anode and cathode ?

  2. Question 2

    Chemical Reactions and Equations. Asked once: 2025 (same type asked 3 times)

    1
    The main observations while performing the experiment of burning magnesium ribbon in air are : (i) Magnesium ribbon burns with a dazzling white flame. (ii) A white powder is formed. (iii) Magnesium ribbon vapourises. (iv) Aqueous solution of the white powder turns blue litmus to red.

    Tap an option to check your answer.

  3. Question 3

    Chemical Reactions and Equations. Asked once: 2024 (same type asked 3 times)

    34 (a)
    What is a chemical reaction ? Describe one activity each to show that a chemical change has occurred in which (i) change of colour, and (ii) change in temperature has taken place.

  4. Question 4

    Control and Coordination. Asked once: 2024 (same type asked 3 times)

    35 (b)
    (i) Leaves of ‘chhui-mui’ plant begin to fold up and droop in response to a stimulus. Name the stimulus and write the cause for such a rapid movement. Is there any growth involved in the movement ? (ii) Define geotropism in plants. What is meant by positive and negative geotropism ? Give one example of each type.

  5. Question 5

    Electricity. Asked once: 2024 (same type asked 3 times)

    26
    State Joule’s law of heating. How is this effect useful in electric circuits where fuse is used as a safety device ?