Question

The radius of curvature of the convex surface of a thin plano-convex lens is 15 cm and the refractive index of its material is 1.6. The power of the lens is
A. `+1D`
B. `-2D`
C. `+3D`
D. `+4D`

Answer 1

Correct Answer - D

`(1)/(f)=(``_amu_g-1)((1)/(R)-(1)/(infty))`
`=(1.6-1)((1)/(15))=(6)/(150)`
`P=(100)/(f(cm))D=100xx(6)/(150)=4D`