Assertion : The resolving power of a telescope is more if the diameter of the objective lens is more.
Reason : Objective lens of large diameter collectd more light.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false

Answer

A

Explanation

Resolving power of telescope `=(D)/(1.22 lamda)` where D is the diameter of the objective lens and `lamda` is the wavelength of the light used.
With increase in D, resolving power of telescope increases. A telescope will have large light garthering power if the diameter of the objective lens is large. Hence a bright image will be formed by the telescope.