Question

Find the angle of deviation suffered by the light ray shown in figure. The refractive index μ = 1.5 for the prism material.

Answer 1

Given,
The refractive index of the prism material (μ) = 1.5
Angle of prism form the figure = 4˚

We know that,

\[\mu = \frac{\sin\left( \frac{A + \delta_m}{2} \right)}{\sin  \frac{A}{2}}\] 

\[    \mu = \frac{\left( \frac{A + \delta_m}{2} \right)}{\frac{A}{2}}  \left( \text{ because for  small  angle } \sin  \theta \approx \theta \right)\] 

\[       = \frac{A + \delta_m}{2^\circ }\] 

\[1 . 5 = \frac{4^\circ + \delta_m}{2^\circ}\] 

\[ \delta_m  = 2^\circ \]
Hence, the angle of deviation is 2˚