Magnification produced by astronominal telescope for normal adjustment is 10 and length of telescope is 1.1m. The magnification when the image is formed at least distance of distinct vision `(D = 25cm)` is-

Options

A. 14
B. 6
C. 16
D. 18

Answer

A

Explanation

`(f_(0))/(f_(e)) = 10`
`f_(0) +f_(e) = 1.1`
`:.f_(0) = 100 cm` and `f_(e) = 10cm`
Final magnification `= f_(0) ((1)/(D)+(1)/(f_(e)))`
`=100 [(1)/(25)+(1)/(10)] = 14`