Question

when white light is incident on a glass slab and emerges after the reflection, it does not from a spectrum.explain.​

Answer 1

Explanation:

A glass prism is able to produce a spectrum , which is a patch of light obtained due to dispersion. This is because the opposite refracting faces of a glass prism are not parellal. Thus, the incident ray is not parellal to the emergent ray and is deviated by the angle of deviation.

A glass slab is a rectangular structure in which the opposite refracting faces are parellal to each other. The result is that , the emergent is parellal to the incident ray but is literally displaced from it.

Thus, a rectangular glass slab is unable to produce a spectrum due to the refracting faces being parellal to each