If the focal length of the ey piece of the telescope is doubled, then its magnifying power (m) will be

Options

A. 2m
B. 3m
C. m/2
D. 4m

Answer

C

Explanation

(c ) The magnifying power (m) of a telescope,m=`-f_(0)/f_(e)`.Now, if the local length of the eye-piece `(f_(e))` is doubled, then the new magnification would be equal to `m'=-f_(0)/(2f_(e))=m/2`