A narrow parallel beam of light falls on a glass sphere of radius R and refractive index `mu` at normal incidence. The distance of the image from the outer edge is given by-

Options

A. `(R(2- mu))/(2(mu - 1))`
B. `(R(2+ mu))/(2 (mu - 1))`
C. `(R(2 - mu))/(2(mu + 1))`
D. `(R(2 + mu))/(2(mu + 1))`

Answer

A

Explanation

Now `(mu)/(V_(1)) - (1)/(infty) = (mu - 1)/( R) rArr V_(1) = (muR)/(mu - 1)`
Now `(1)/(V_(1)) - (mu)/(- (2R - V_(1)) ) = (1- mu)/( - R) `
Replace `V_(1) ` by `(muR)/( mu - 1)` and solving for `V_(1)`
We get `V_(f) = (R(mu - 2))/(2 (mu - 1))`
First image is real and second is virtual.