Question

The length of the tube of a compound microscope $15cm$. The focal length of objective and eye lenses are 1 cm and $5cm$ respectively. The magnifying power of microscope for relaxed vision is:

• A. $50cm$
• B. $75cm$
• C. $25cm$
• D. $100cm$

Answer 1

The correct option is B $75cm$

Given, $L=15cm$
$f_0=1cm$
$f_e=5cm$
$D=25cm$
so, $m=\frac{L}{f_0}\frac{D}{f_e}$
$=\frac{15\times 25}{1\times 5}$
$=75cm$