Question

A submarine periscope uses two totally reflecting 45-45-90 prisms with total internal reflection on the sides adjacent to the 45 degree angles. Explain why the periscope will no longer work if it springs a leak and the bottom prism is covered with water. Note: The index of refraction for water is 1.33. The index of refraction for glass is 1.52

Answer 1

Answer

Given,

Periscope uses 45-45-90 prisms with total internal reflection adjacent to 45°.

refractive index of water, n_a = 1.33

refractive index of glass, n_g = 1.52

When the light enters the water, water will act as a lens and when we see the object from the periscope the object shown is farther than the usual distance.