Question

A microscope consists of an objective with a focal length $2$ mm and an eye piece with a focal length $40$ mm. The distance between the foci(which are between the lenses) of objective and eyepiece is $18$cm. The total magnification of the microscope is(Consider normal adjustment and take $D=25$cm)

• A. $562.5$
• B. $625$
• C. $265$
• D. $62.5$

Answer 1

The correct option is A $562.5$

$m=\frac{LD}{f_o{f}_e}$

where l is the distance between focaii least distance of distinctof termssub the values getting

$=\frac{18\times 25}{0.2\times 4}$

$m=562.5$