Question

A convex lens of focal length $12.5cm$ is used as a simple microscope. When the image is formed at infinite. Magnification is ________ (Near point for the normal vision is $25cm$)

• A. $25$
• B. $2.5$
• C. $2.0$
• D. $1.0$

Answer 1

Answer: (C)

$2.0$

Given:

The distance of the normal vision is $25cm$.

The focal length of the convex lens is $12.5cm$

The magnification of the microscope to produce image at infinity is:

$M=\frac{D}{f}=\frac{25}{12.5}$
$M=2$