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`.

Explanation

Since, `theta = (122lambda)/(a)`
`therefore` `theta= (1.22xx555 xx 10^(-9))/(0.25)rad` `theta=2.7xx10^(-6)rad`.