Wave Optics - Result Question 23

24. Assume that light of wavelength $600 nm$ is coming from a star. The limit of resolution of telescope whose objective has a diameter of $2 m$ is :

[2020]

(a) $1.83 \times 10^{-7} rad$

(b) $7.32 \times 10^{-7} rad$

(c) $6.00 \times 10^{-7} rad$

(d) $3.66 \times 10^{-7} rad$

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Answer:

Correct Answer: 24. (d)

Solution:

  1. (d) Given:

Wavelength, $\lambda=600 nm=600 \times 10^{-9} m$

and diameter of objective, $d=2 m$

Limit of resolution of telescope,

$\theta=\frac{1.22 \lambda}{d}=\frac{1.22 \times 600 \times 10^{-9}}{2}=3.66 \times 10^{-7} rad$