Question

A boy of height 1m stands in front of a convex mirror. His distance from the mirror is equal its focal length. The height of his image is

• A. 0.25m
• B. 0.5m
• C. 0.33m
• D. 0.67m

Answer 1

The correct option is B

0.5m

using mirror formula: $\frac{1}{v}+\frac{1}{-f}=\frac{1}{f}V=\frac{f}{2}$
where 'v' is the image distance, 'u' is the object distance and 'f' is the focal length of the mirror
$\frac{1}{v}+\frac{1}{-f}=\frac{1}{f}V=\frac{f}{2}$
We write magnification as $\frac{v_i}{h_0}=-\frac{v}{u}$ where$h_i$ is the height of image and $h_o$ is the height of object. Placing the value of v, we can get $h_i=\frac{1}{2}$