Question

The linear magnification for a mirror is the ratio of the size of the image to the size of the object and is denoted by m. Then m is equal to

• A. $\frac{f}{f-u}$
• B. $\frac{f-u}{f}$
• C. $\frac{f}{f+v}$
• D. $\frac{f+v}{f}$

Answer 1

The correct option is A $\frac{f}{f-u}$

The magnification is given as
$m=-\frac{v}{u}$
From mirror formula
$\frac{1}{v}+\frac{1}{u}=\frac{1}{f}v=\frac{fu}{u-f}$
Therefore, magnification
$m=\frac{f}{f-u}$
Therefore, Option A is correct.