Question

A wire mesh consisting of very small squares is viewed at a distance of 8 cm through a magnifying converging lens of focal length 10 cm, kept close to the eye. The magnification produced by the lens is.

• A. 5
• B. 8
• C. 10
• D. 20

Answer 1

The correct option is A 5

Using $\frac{1}{v}-\frac{1}{u}=\frac{1}{f}$

$\frac{1}{v}+\frac{1}{8}=\frac{1}{10}$

$\frac{1}{v}=\frac{1}{10}-\frac{1}{8}=\frac{4-5}{40}=-\frac{1}{40}$

$v=-40cm$

$m=\frac{v}{u}=\frac{40}{8}=5$.