Determine the angle of deviation experienced by the light ray depicted in the figure. The prism material has a refractive index = 1.5 .

Step-by-step solution

The light ray is incident normally on the first face of the prism, so the angle of incidence i₁ = 0^ and the angle of refraction r₁ = 0^ . For a prism, the refracting angle A = r₁ + r₂ . Given A = 4^ , we have r₂ = 4^ . Applying Snell's law at the second face: (r₂) = (e) Since the angles are small, ( ) : r₂ = e 1.5 4^ = e e = 6^ The angle of deviation is: = i₁ + e - A = 0^ + 6^ - 4^ = 2^ Alternatively, for a thin prism, the deviation is directly given by: = ( - 1)A = (1.5 - 1) 4^ = 2^