Assuming the mean wavelength of light as `555 nm`, estimate the smallest angular separation of two stars which can be just resolved by the telescope. Given the diameter of objective of astronomical telescope is `25 cm`.

Options

A. `2.7 xx 10^(6)` rad
B. `1.5 xx 10^(-6)` rad
C. `2.7 xx 10^(-6)` rad
D. `3.1 xx 10^(6)` rad

Answer

C

Explanation

`theta = (1.22 lambda)/(D) = (1.22 xx 555 xx 10^(-2))/(25 xx 10^(-2))`
`theta = 2.7 xx 10^(-6)` rad