Physics - Geometrical Optics Question with Solution | TestHub

Given angle of incidence $i=60^{\circ }$

Angle of prism $A=30^{\circ }$

Angle of deviation $\delta =30^{\circ }$

Using the relation for a prism, $\delta =i+e-A$

$30^{\circ }=60^{\circ }+e-30^{\circ }$

$e=0^{\circ }$

Since the angle of emergence is zero, the ray emerges normally from the second face, which means $r_2=0^{\circ }$.

Using the relation $r_1+r_2=A$

$r_1+0^{\circ }=30^{\circ }$

$r_1=30^{\circ }$

Applying Snell's law at the first face:

$\mu =\frac{\sin i}{\sin r_1}=\frac{\sin 60^{\circ }}{\sin 30^{\circ }}$

$\mu =\frac{\sqrt{3}/2}{1/2}=\sqrt{3}=1.732$

Answer: 1.732