devarshi-dt-logo

Question:

You are given two converging lenses of focal lengths 1.25 cm and 5 cm to design a compound microscope. If it is desired to have a magnification of 30, find out the separation between the objective and the eyepiece.

Solution:

Magnification of a compound microscope is given by:
M=MoMe ≈ −L/fo * 25/fe
Substituting values,
30=L × 25/(1.25 × 5)
L=7.5 cm