A mark placed on the surface of a sphere is viewed through glass from a position directly opposite. If the diameter of the sphere is `10 cm` and refractive index of glass is `1.5`, find the position of the image.

Explanation

Here, `u = -10 cm, R = -5 cm`
`mu_2 = 1.5, mu_1 = 1, v = ?`
In the present case, refraction occurs from denser to rarer medium.
`:. (mu_2)/(-u)+(mu_1)/(v)=(1 - 1.5)/(-5)=(1)/(10)`
or `(1)/(v) =(1)/(10)-(3)/(20)=-(1)/(20)`
`:. v = -20 cm`.