Question

All ray diagram and numerical of light refraction and reflection

Answer 1

Q2:When a bright object is placed 10 cm away from a concave mirror, its real image is formed at a distance 40cm from the mirror. What is the focal length of the mirror?

Answer 2

By using mirror formula,

1/f = 1/v + 1/u

1/f = 1/40 - 1/10

1/f = 1-4/40

1/f = -3/40

f = -40/3

f = -13.3 cm

(-)ve sign shows we have used concave mirror