Question

A compound microscope consists of an objective lens with focal length 1.0 cm and eye piece of focal length 2.0 cm and a tube length 20 cm the magnification will be :

• A. 100
• B. 200
• C. 250
• D. 300

Answer 1

Answer: (C)

250

Answer 2

: magnification, of compound microscope

$m = m_{0} \times m_{e} = \left( \frac{L}{f_{o}} \right) \times \left( \frac{D}{f_{e}} \right)$

Here, L = 20 cm, D = 25 cm (near point),

$f_{o} = 1cm$ and $f_{e} = 2cm$

$\therefore m = \frac{20}{1} \times \frac{25}{2} = 250$