Question

(i) What is meant by resolving power of a telescope?
(ii) State any one method of increasing the resolving power of an astronomical telescope.

Answer 1

(i) Resolving power is the reciprocal of the smallest angular separation between two distant object which can be observed distinctly using a telescope. 

If θ `[=(1.22lambda)/D]` be the angular separation, then resolving power = `1/theta = D/(1.22lambda)`;

[D =Aperture of objective lens] 

(ii) By taking large aperture i.e., increasing the size of the aperture the resolving power of lens is increased.