A spherical surface of radius of curvature R separates air (refractive index 1.0) from glass (refractive index 1.5). The centre of curvature is in the glass. A point object P placed in air is found to have a real image Q in the glass. The line PQ cuts the surface at a point O, and `PO=OQ`. The distance `PO`

Options

A. 5R
B. 3R
C. 2R
D. 1.5R

Answer

A

Explanation

Using, `(mu)/(v)-(1)/(u)=(mu-1)/(R )`
`or (1.5)/(x)-(1)/(-x)=((1.5-1))/(R )`
`therefore" "x=5R`