Question

A spherical convex surface separates object and image space of refractive index `1.0 and 4/3.` If radius of curvature of the surface is `10cm,` find its power.

Answer 1

Correct Answer - `2.5 D`
Here, `mu_1 = 1.0, mu_2 = 4//3, R = 10 cm. P = ?`
Refraction from rarer to denser medium,
`-(mu_1)/(u)+(mu_2)/(v)-(mu_2 - mu_1)/( R)` when `u = oo, v = f`
`:. -(1)/(oo)+(4)/(3 f) = (4//3 - 1)/(10) = (1)/(30) , (1)/(30) , f = 40 cm`
`P = 100//f = (100)/(40) = 2.5 D`.