An image is formed at a distance of 100 cm from the glass surface when light from point source in air falls on a spherical glass surface with refractive index 1.5. The distance of the light source from the glass surface is 100 cm. The radius of curvature is

Options

A. 20 cm
B. 40 cm
C. 30 cm
D. 50 cm

Answer

A

Explanation

The refraction formula is, `(mu_(2))/(v)=(mu_(1))/(u)=(mu_(2)-mu_(1))/(R)`
where, R=radius of curvature
Given, u=100 cm, v=100 cm, `mu_(2)=1.5, mu_(1)(air)=1`
`Rightarrow (1.5)/(100)+(1)/(100)=(1.5-1)/(R)Rightarrow(2.5)/(100)=(0.5)/(R)`
`R=(0.5xx100)/(25)Rightarrow=20 cm`