Question

The radius of curvature of a convex spherical mirror is $1.2m$ How far away from the mirror is an object of height $12cm$ if the distance between its virtual image and the mirror is $0.35m$ ? What is the height of the image?

Answer 1

Since radius of curvature is $1.2m$ i.e. $120cm$.

Therefore focal length$=-60cm$

From mirror formula

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

$\frac{1}{-35}+\frac{1}{u}=\frac{1}{-60}$

$\frac{1}{u}=\frac{1}{35}-\frac{1}{60}$

$\frac{1}{u}=\frac{12-7}{420}$

$u=84cm$

Image height$=\frac{12}{84}\times 35=5cm$

Thus image height will be 5 cm.