Q2Multiple choice
A 10 mm long awl pin is placed vertically in front of a concave mirror. A 5 mm long image of the awl pin is formed at 30 cm in front of the mirror. The focal length of this mirror is
- (a)– 30 cm
- (b)– 20 cm
- (c)– 40 cm
- (d)– 60 cm
Show answer
(b) – 20 cm