Question

A convex mirror used as a rear-view mirror of a car has a focal length of 2m. If a bus is located at a distance of 3m from the mirror, where will its image be formed?

• A. 0.83 m in front of the mirror
• B. 1.2 m in front of themirror
• C. 0.83 m behind the mirror
• D. 1.2m behind the mirror

Answer 1

Answer:

D. 1.2m behind the mirror

.We know that,

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

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

$\frac{1}{v}=\frac{1}{2}-\frac{1}{-3}$

$\frac{1}{v}=\frac{3+2}{6}$

$\frac{1}{v}=\frac{5}{6}$

$v=0.83m$

Magnification $=\frac{-(image distance)}{object distance}$

$=\frac{-(0.83)}{-3}$

$=1.2m behind the mirror