Question

An object is placed at a distance of 15 cm from a concave mirror and its real image is formed at 30 cm in front of that mirror. The focal length of the mirror is

Answer 1

Answer:

2 cm is the focal length of the mirror.

Answer 2

Answer:

u= -15

v=-30

f=?

1/v+1/u=1/f

1/-30+1/-15=1/f

1/30+1/15=1/f

3/30=1/f

1/10=1/f

f=10