An astronimical telescope is to be designed to hve a magnifying power of 50 in normal adjustment. If the length of the tube is 102 cm, fid the powers of the objective and the eyepiece.

Answer

`1 D` ; `50 D`

Explanation

Here, `m = - 50, L = 102 cm`
As `m = -(f_(0))/(f_(e)) = - 50, f_(0) = 50 f_(e)`
Also, `L = f_(0) + f_(e) = 102` ,
`50 f_(0) + f_(e) = 102, f_(e) = 2 cm`
`f_(0) = 50 f_(e) = 50 xx 2 = 100 cm`
`P_(0) = (100)/(f_(0)) = (100)/(100) = 1 D, P_(e) = (100)/(f_(e)) = (100)/(2) = 50 D`