Q.
In a compound microscope, the focal length of the objective lens and the eye lens are 4mm and 25mm and the length of the tube is 16cm . For relaxed eye position, find its magnifying power.
fo=4mm=0.4cm fe=25mm=2.5cm
Length of the tube, Lt = 16cm
Magnifying power for relaxed eye position is given by: m=fofe(Lt−fo−fe)D m=0.4×2.5(16−0.4−2.5)×25 m=327.5