PYQ Vault

Day 202: CBSE Class 10 Science

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

  1. Question 1

    Chemical Reactions and Equations. Asked once: 2023 (same type asked 3 times)

    30
    With the help of an appropriate example, justify that some of the chemical reactions are determined by (a) Change in temperature, (b) Evolution of a gas, and (c) Change in colour Give chemical equation for the reaction involved in each case.

  2. Question 2

    Electricity. Asked once: 2025 (same type asked 3 times)

    25 (a)
    A wire of resistance R is cut into three equal parts. If these three parts are then joined in parallel, calculate the total resistance of the combination so formed.

  3. Question 3

    Light — Reflection and Refraction. Asked once: 2023 (same type asked 3 times)

    30 (A)
    An object is kept at a distance of 1m from a lens of power +2D : (i) Identify the type of lens. (ii) Calculate its focal length and distance of the image formed.

  4. Question 4

    Light — Reflection and Refraction. Asked once: 2024 (same type asked 3 times)

    31 (a)
    An object is placed in front of a concave mirror of focal length 12 cm. If distance of the object from the pole of the mirror is 8 cm, then use mirror formula to determine the position of the image formed. Draw a labelled ray diagram to justify your answer in this case.

  5. Question 5

    Metals and Non-metals. Asked once: 2025 (same type asked 2 times)

    22 (A)
    Show the formation of calcium chloride by the transfer of electrons from one element to the other. Atomic Number of calcium and chlorine is 20 and 17 respectively.