Question

When diameter of the aperture of the objective of an astronomical telescope is increased, its : 

(a) magnifying power and resolving power both are increased 

(b) magnifying power remains the same but resolving power is increased 

(c) magnifying power and resolving power both are decreased 

(d) magnifying power is increased and resolving power is decreased

Answer 1

Correct option (a) magnifying power and resolving power both are increased

Explanation:

Since, intensity ∝ (diameter of the lens) 2 , therefore, diameter of aperture of the objective lens should be large, so, that more and more rays may enter in the telescope and hence, the intensity of image gets increased. Also resolving power is also increased.