Question

(ii) Show ray diagram for the refraction of a light ray through a prism and point out the emergent angle and angle of deviation.

Answer 1

When a light ray passes through a prism, it undergoes refraction at both the faces of the prism. The light ray bends towards the base of the prism when it enters, and then bends away from the base when it exits. This change in direction causes the ray to deviate from its original path. Explanation:
- \( i \): Angle of incidence (angle between the incident ray and the normal to the surface of the prism)
- \( r_1 \): Angle of refraction at the first surface (angle between the refracted ray and the normal to the surface)
- \( A \): Angle of the prism (the angle between the two sides of the prism)
- \( r_2 \): Angle of refraction at the second surface
- \( e \): Emergent angle (the angle between the refracted ray inside the prism and the normal at the second surface)
- \( \delta \): Angle of deviation (the total angle by which the light ray has deviated from its original path)
Emergent Angle and Angle of Deviation:
The emergent angle is the angle between the refracted ray and the normal to the second surface. The angle of deviation, \( \delta \), is the total deviation of the light ray as it passes through the prism and exits. The angle of deviation depends on the angle of the prism \( A \), the angle of incidence, and the refractive index of the material of the prism. % Topic - Optics: Refraction through a Prism \vspace{0.5cm} \hrule \vspace{0.5cm} 3.