Question

A point object is placed at a distance of 30 cm from a convex mirror of focal length 30cm. The image will form at

• A. Infinity
• B. 15 cm infront of the mirror
• C. Pole
• D. 15 cm behind the mirror

Answer 1

The correct option is D 15 cm behind the mirror

u=-30 cm, f =+30 cm,by using mirror formula
$\frac{1}{f}=\frac{1}{v}+\frac{1}{u}\Rightarrow \frac{1}{+30}=\frac{1}{v}+\frac{1}{(-30)}$
v=15 cm, behind the mirror