1. Tardigrade
  2. Question
  3. Physics
  4. A man has a concave shaving mirror or focal length 0.2 m. How far should the mirror be held from his face in order to give an image of two fold magnification?

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. A man has a concave shaving mirror or focal length $0.2 \,m$. How far should the mirror be held from his face in order to give an image of two fold magnification?

Ray Optics and Optical Instruments

Solution:

As, $m =\frac{f}{f-u}$
$\Rightarrow 2=\frac{-0.2}{-0.2-u}$
or $2=\frac{0.2}{0.2+u}$
or $0.4+2 u=0.2$
Or $2 u=0.2-0.4=-0.2$
Or $u=-0.1 \,m$