Question

A convex mirror has a focal length f. A real object is placed at a distance f/2 in front of it from the pole. The mirror produces an image at

• A. $3f$
• B. $f$
• C. $2f$
• D. $f/3$

Answer 1

Answer: (D)

$f/3$

Given,

Focal length $=f$

Object distance $u=-\frac{f}{2}$

Lens formula,

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

$\frac{1}{v}-\frac{2}{f}=\frac{1}{f}$

$\frac{1}{v}=\frac{-3}{f}$

$v=\frac{f}{3}$

Option D