An astronomical telescope has an angular magnification of magnitude `5` for distant object. The separation between the objective and eyepiece is `36cm` and the final image is formed at infinity. Determine the focal length of objective and eyepiece.

Options

A. `f_(0)`=45 cm and `f_(0)`=-9 cm
B. `f_(0)=` 50 cm and `f_(0)=`10 cm
C. `f_(0)=7.2 cm` and `f_(0)=5cm`
D. `f_(0)`=30 cm and `f_(0)`=6cm

Answer

D

Explanation

`M=(f_(o))/(f_(theta))=5`
`f_(o)+f_(theta)=36`
`f_(theta)=6 cm`
`f_(o)=30 cm`