You are asked to design a shaving mirror assuming that a person keeps it `10cm` from his face and views the magnified image of the face at the closest comfortable distance of `25cm`. The radius of curvature of the mirror would then be:

Options

A. 60 cm
B. `-24cm`
C. `-60cm`
D. 24 cm

Answer

C

Explanation

Convex morror is used as a shaving mirror.

From question : `v=15cm, u=-10cm`
Radius of curvature, `R=2f=?`
Using mirror formula, `(1)/(v)+(1)/(u)=(1)/(f)`
`(1)/(15)+(1)/((-10))=(1)/(f) rArr f=-30cm`
Therefore radius of curvature,
`R=2f=-60cm`