Calculate the limit of resolution of a telescope objective lens having a diameter of 200 cm, if it has to detect light of wavelength 500 nm coming from a star.

Options

A. `457.5 xx 10^(-9)` radian
B. `610 xx 10^(-9)` radian
C. `305 xx 10^(-9)` radian
D. `152.5 xx 10^(-9)` radian

Answer

C

Explanation

Limit of resolution of telescope is given by
`theta = (1.22 lambda)/D`
`theta = (1.22 xx 500 xx 10^(-9))/(200 xx 10^(-2)) = 305 xx 10^(-9)` radian.