PYQ Vault

Day 197: CBSE Class 10 Science

5 questions (11 parts). Try each one first, then open its answer.

  1. Question 1 (case study, 4 parts)

    The Human Eye and the Colourful World. Asked once: 2025 (same type asked 4 times)

    The students in a class took a thick sheet of cardboard and made a small hole in its centre. Sunlight was allowed to fall on this small hole and they obtained a narrow beam of white light. A glass prism was taken and this white light was allowed to fall on one of its faces. The prism was turned slowly until the light that comes out of the opposite face of the prism appeared on the nearby screen. They studied this beautiful band of light and concluded that it is a spectrum of white light.
    39 (i)
    Give any one more instance in which this type of spectrum is observed.
    39 (ii)
    What happens to white light in the above case?
    39 (iii) (A)
    List two conditions necessary to observe a rainbow.
    39 (iii) (B)
    Draw a ray diagram to show the formation of a rainbow. Mark on it, points (a), (b) and (c) as given below : (a) Where dispersion of light occurs. (b) Where light gets reflected internally. (c) Where final refraction occurs.

  2. Question 2

    The Human Eye and the Colourful World. Asked once: 2024 (same type asked 4 times)

    25
    Name the phenomenon of light responsible for Tyndall effect. Write an event where this phenomenon can be observed.

  3. Question 3

    The Human Eye and the Colourful World. Asked once: 2025 (same type asked 4 times)

    Two statements are given, one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the options given below.
    20
    Assertion (A) : When ciliary muscles contract, eye lens becomes thin. Reason (R) : Ciliary muscles control the power of the eye lens.

    Tap an option to check your answer.

  4. Question 4

    Electricity. Asked once: 2022 (same type asked 4 times)

    12 (b)
    (i) State Joule’s law of heating. Express it mathematically when an appliance of resistance R is connected to a source of voltage V and the current I flows through the appliance for a time t. (ii) A 5 Ω5\,\Omega resistor is connected across a battery of 6 volts. Calculate the energy that dissipates as heat in 10 s.

  5. Question 5 (case study, 4 parts)

    Electricity. Asked once: 2022 (same type asked 4 times)

    Study the following electric circuit in which the resistors are arranged in three arms A, B and C :
    14 (a)
    Find the equivalent resistance of arm A.
    14 (b)
    Calculate the equivalent resistance of the parallel combination of the arms B and C.
    14 (c) (i)
    Determine the current that flows through the ammeter.
    14 (c) (ii)
    Determine the current that flows in the ammeter when the arm B is withdrawn from the circuit.