If the focal length of the objective lens is increased then

Options

A. Microscope will telescope both will decrease
B. Microscope and telescope both will increase
C. Microscope and telscope both will decrease
D. Microscope will decrease but that of telescope will increase.

Answer

D

Explanation

Magnifying power of microscope
`=(LD)/(f_(o)f_(e))prop(1)/(f_(o))`
Hence with the increase of `f_(0)`, magnifying power of microscope decreases.
Magnifying power of telescope`=(f_(o))/(f_(e))propf_(o)`
Hence with the increase of `f_(o)` magnifying power of telescope increases.