Diameter of the objective lens of a telescope is 250 cm. for light of wavelength 600 nm. Coming from a distance object, the limit of resolution of the telescope is close to :

Options

A. ` 1 . 5 xx 10 ^(-7)` rad
B. ` 4 . 5 xx 10 ^(-7)` rad
C. `3 . 0 xx 10 ^(-7) ` rad
D. `2 . 0 xx 10 ^(-7)` rad

Answer

C

Explanation

Limit of resolution ` - (1.22 lambda)/(D)`
`= (1 . 22 xx 600 xx 10 ^(-9))/( 2.5) = 2.928 xx 10^(-7) ~~ 3 xx 10^(-7) rad `