Question

Example 9.6 Light from a point source in air falls on a spherical
glass surface (n = 1.5 and radius of curvature = 20 cm). The distance
of the light source from the glass surface is 100 cm. At what position
the image is formed?​

Answer 1

◆ Answer-

v = 1 m

◆ Explaination-

# Given-

For air, n1 = 1

For glass, n2 = 1.5

R = 20 cm = 0.2 m

u = -100 cm = -1 m

# Solution-

Using formula for refraction at single spherical surface -

n2/v - n1/u = (n2-n1)/R

1.5/v + 1/1 = (1.5-1)/0.2

1.5/v = 2.5 - 1

v = 1.5/1.5

v = 1 m

v = 100 cm

Image will be formed at 1 m.