The image formed by a convex mirror of focal length 30 cm is a quarter of the size of the object. The distance of the object from the mirror is

Options

A. 30cm
B. 60cm
C. 90cm
D. 120cm

Answer

C

Explanation

Given, f=+30cm and `m=(1)/(4)`
Magnification, `m=(f)/(f-u)`
`therefore (30)/(30-u)=(1)/(4)`
30-y=120 `Rightarrowu=-90cm`