Light from a point source in air falls on a convex spherical glass surface `(mu = 1.5 and R = 20 cm)`. Calculate position of the image when the light source is at `1m` from the glass surface.

Explanation

Here, `mu_1 = 1,mu_2 = 1.5`,
`R = 0.2 m = 20 cm, v = 100 cm, u = ?`
As refraction occurs from rarer to denser medium,
`(mu_1)/(-u)+(mu_2)/(v) =(mu_2 - mu_1)/( R)`
`(1)/(-u)+(1.5)/(100) =(1.5 - 1)/(20)=(1)/(40)`
`-(1)/(u)=(1)/(40)-(3)/(200)=(2)/(200)=(1)/(100)= -100 cm`
`:.` Distance of object from pole spherical surface is `100 cm`
Distance of object from the centre of spherical surface `= 100 + 20 = 120 cm`.