PYQ Vault
EbooksTutor

Minimum separation resolved by an eye or a telescope (Rayleigh criterion)

This type of question, asked 2 times: 22 Apr 2025 S1, 11 Apr 2026 S2. All 2 questions below, oldest first.

Try each one first, then open its answer.

  1. Question 1

    22 Apr 2025 S1

    6
    Assuming human pupil to have radius of 0.25 cm and comfortable viewing distance of 25 cm , the minimum separation between the two objects that human eye can resolve at 500 nm wavelength is nearly

    Tap an option to check your answer.

  2. Question 2

    11 Apr 2026 S2

    143
    Converging lens of telescope 55 cm in diameter has focal length 2525 cm. In the focal plane of the lens the distance between the centres of the Fraunhofer diffraction pattern is (wavelength of light used = 50005000 A˚\mathrm{\mathring{A}}, Rayleigh's criterion is satisfied)

    Tap an option to check your answer.