For compound microscope `f_(0) = 1 cm, f_(e) = 2.5 cm`. An object is placed at distance 1.2 cm from objective lens. What should be length of microscope for normal adjustment?

Options

A. 8.5 cm
B. 8.3 cm
C. 6.5 cm
D. 6.3 cm

Explanation

In the normal adjustment of a compound microscope, `L = v_(o) + v_(e) = (v_(o)f_(e))/(v_(o) + f_(e)) + f_(e)`
` = (-1.2 xx 1)/(-1.2 + 1) + 2.5 = 6 + 25 = 8.5 cm`