Physics - Geometrical Optics Question with Solution | TestHub

The image is inverted and magnified ($\frac{6}{3}=2$), so the mirror is concave with $m=-2$, giving $v=2u$.

Object and image are 30 cm apart, so $v-u=30$ gives $u=30$ cm and $v=60$ cm - (C) and (D) correct.

$\frac{1}{f}=\frac{1}{v}+\frac{1}{u}=\frac{1}{60}+\frac{1}{30}$ gives $f=20$ cm, i.e. a concave mirror of radius 40 cm - (A) correct.