PYQ Vault

Day 31: CBSE Class 10 Science

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

  1. Question 1

    Our Environment. Asked 2 times: 2023*, 2025 (* = numbers or wording changed that year)

    26
    (a) Why are the organisms of first trophic level important in any food chain ? (b) Justify the following statement : ‘The flow of energy in an ecosystem is unidirectional.’

  2. Question 2

    The Human Eye and the Colourful World. Asked 2 times: 2024*, 2025 (* = numbers or wording changed that year)

    32
    A person uses lenses of +2.0+2.0 D power in his spectacles for the correction of his vision. (a) Name the defect of vision the person is suffering from. (b) List two causes of this defect. (c) Determine the focal length of the lenses used in the spectacles.

  3. Question 3

    The Human Eye and the Colourful World. Asked 2 times: 2024*, 2025 (* = numbers or wording changed that year)

    14
    Most of the refraction for the light rays entering the eye occurs at

    Tap an option to check your answer.

  4. Question 4

    The Human Eye and the Colourful World. Asked 2 times: 2024*, 2025 (* = numbers or wording changed that year)

    12
    When a beam of white light passes through a region of very fine dust particles, the colour of light that scatters the most in that region is :

    Tap an option to check your answer.

  5. Question 5

    How do Organisms Reproduce?. Asked 2 times: 2024*, 2025 (* = numbers or wording changed that year)

    30
    (a) What are chromosomes ? (b) Explain in brief how stability of DNA content of a species is ensured in sexually reproducing organisms ?