Magnification of a compound microscope is 30. Focal length of eye`-` piece is `5 cm` and the image is formed at a distance of distinct vision of `25 cm`. The magnificatio of the objective lens is

Options

A. `6`
B. `5`
C. `7.5`
D. `10`

Answer

B

Explanation

Here, `m = 30, f_(e) = 5 cm, d = 25 cm`
As `m_(e) = 1 + (d)/(f_(e)) = 1 + (25)/(5) = 6`
As `m = m_(e) xx m_(0), :. 30 = 6 xx m_(0)`
`m_(0) = (30)/(6) = 5`