A concave mirror forms on a screen an image of size twice

Last updated: 6/24/2023

A concave mirror forms on a screen an image of size twice that of the real object The mirror is kept stationary while the object and the screen are moved until an image of size thrice that of the object is formed on the screen If the screen displacement is 30 cm the focal length of the mirror is nearest to A 60 cm B 50 cm C 40 cm D 30 cm