Question

Four convergent lenses have focal lengths `100cm, 10cm, 4cm` and `0.3cm`. For a telescope with maximum possible magnificaiton, we choose the lenses of focal lengths
A. `100cm, 0.3cm`
B. `10cm, 0.3cm`
C. `10cm, 4cm`
D. `100cm, 4cm`

Answer 1

Correct Answer - A
`m =- (f_(0))/(f_(e))`, for `m` to be maximum, `f_(0)` should be maximum and `f_(e)` should be minimum.
`f_(0) = 100cm, f_(e) = 0.3 cm`