Question

It the focal length of objective lens is increased then magnifying power of : 

(A) microscope will increase but that of telescope decrease 

(B) microscope and telescope both will increase 

(C) microscope and telescope both will decrease 

(D) microscope will decrease but that of telescope will increase. 

Answer 1

Correct option: (D) microscope will decrease but that of telescope will increase.

Explanation:

M.P. of a microscope = (L / f_o) (D / f_e)

if f₀ ↑ ⇒ M.P. of the microscope will decrease

M.P. of telescope =  f_o / f_e 

if f₀ ↑ ⇒ M/O. of telescope will increase.