Q 12-09-019NEETJEE MainEasy
An object is placed $30$ cm in front of a concave mirror of focal length $20$ cm. The image is formed at
Answer: (B) $60$ cm in front of the mirror, real and inverted
$\dfrac{1}{v} + \dfrac{1}{u} = \dfrac{1}{f}$ with $u = -30$, $f = -20$: $\dfrac{1}{v} = -\dfrac{1}{20} + \dfrac{1}{30} = -\dfrac{1}{60}$, so $v = -60$ cm: real, in front, magnified ($m = -2$) and inverted.
Solution by Sreeraj P, M.Sc Physics