Magnification of a compound is 30. Focal length of eyepiece is 5 cm and the image is formed at a distance of distinct vision of 25 cm. The magnification of the objective lens is

Options

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

Explanation

`m_(e)=(v)/(u)=(D)/(u_(c))=1+(D)/(f_e)=1+(25)/(5)=6`
for the compound microscope , `m = m_(o) xx m_(e) rArr = 30 = m_(a) xx 6 (or) m_(o) = 5`