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`.