Question

A beam of blue light in air is incident on a glass plate. Will the transmitted beam emerge shifted laterally (sideways) from the direction of the incident beam?A. Yes B. No

Answer 1

Answer:

Yes

Explanation:

When any visible light is incident on a (transparent) glass plate then it experiences refraction which is observed in the form of a bending of rays form the first optical medium into the second optical medium when incident at some angle other than normal to the interface.

This occurs because the light rays in experience a change in speed when encountering a change in medium. This is due to the optical density of various medium being different.

• When a light ray enters form a rarer medium (air) to a denser medium (glass) then it bend towards the normal and when it passes from the glass to the air then it bends away from the normal by the same factor. Therefore the incident ray and the emergent ray are shifted and mutually parallel.

The factor is called refractive index, mathematically given as:

$n=\frac{sin\ i}{sin\ r} =\frac{c}{v}$

where:

i = angle of incident (angle between the incident ray and normal to the interface)

r = angle of refraction (angle between the refracted ray and normal to the interface)

c = speed of light in the air

v = speed of light in the medium