PYQ Vault

Day 178: CBSE Class 10 Science

5 questions (8 parts). Try each one first, then open its answer.

  1. Question 1

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

    25
    A person suffering from presbyopia needs bifocal lens. If he needs two lens of power −4⋅0-4{\cdot}0 dioptre and +2⋅0+2{\cdot}0 dioptre, which one of these two lenses is for the correction of distant vision and what is its focal length ?

  2. Question 2 (case study, 4 parts)

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

    A person allowed a narrow beam of white light from the sun to enter a dark room through a small aperture and placed a glass prism in its path in such a manner that the beam falls on the face AB of the prism as shown in the figure. A screen S is placed on the other side of the prism, facing AC. On turning the prism slowly, a beautiful band of colours is obtained on the screen. It is the spectrum of sunlight.
    39 (a)
    Name the phenomenon due to which a prism splits the incident white light into a band of colours.
    39 (b)
    State the reason of getting a band of seven colours in the above case.
    39 (c) (i)
    Explain with the help of a labelled ray diagram, an experimental arrangement to show the recombination of the spectrum of white light.
    39 (c) (ii)
    Draw a labelled ray diagram to show the formation of a rainbow.

  3. Question 3

    The Human Eye and the Colourful World. Asked once: 2024 (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.
    19
    Assertion (A) : Red light signals are used to stop the vehicles on the road. Reason (R) : Red coloured light is scattered the most so as to be visible from a large distance.

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  4. Question 4

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

    13
    The part of the human eye which can modify the curvature of the eye lens to some extent is :

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  5. Question 5

    Electricity. Asked once: 2023 (same type asked 4 times)

    15
    The resistance of a resistor is reduced to half of its initial value. If other parameters of the electrical circuit remain unaltered, the amount of heat produced in the resistor will become :

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