Question

A converging beam of light travelling in air converges at a point P as shown in the figure. When a glass sphere  of refractive index 1 . 5 is introduced in between the path of the beam, calculate the new position of the image. Also draw the ray diagram for the image formed.

Answer 1

Case 1 : n₁ = 1 n₂ = 1.5 

u = ∞

   

${\displaystyle \frac{1.5}{V}=\frac{1}{\infty }=\frac{(1.5-1)}{5}}$ 

${\displaystyle \frac{1.5}{V}=\frac{0.5}{5}}$

V = 15 cm 

case 2 : 

${\displaystyle \frac{1}{V}-\frac{1.5}{15}=\frac{1-1.5}{-5}}$

${\displaystyle \frac{1}{V}=\frac{0.5}{5}+\frac{1.5}{15}}$

${\displaystyle \frac{1}{V}=\frac{1}{20}}$

V = 20 cm