Question

A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The distance of the virtual image from the surface of the sphere is ______.

Options

• 2 cm

• 4 cm

• 6 cm

• 12 cm

Answer 1

A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The distance of the virtual image from the surface of the sphere is 6 cm.

Explanation:

`n_2/v - n_1/u = (n_2 - n_1)/R`

`1/v - 3/(2[-6]) = ([1-3//2])/-6`

`1/v = (-3)/12 + 1/12 = (-2)/12 = (-1)/6`

v = −6 cm