Question

When we place a glass prism in the path of a narrow beam

of white light, a spectrum is obtained. What happens when

a second identical prism is placed in an inverted position

with respect to the first prism? Draw a labelled ray diagram

to illustrate it.​

Answer 1

Answer:

We get back the white light

Explanation:

When two identical prisms are placed in such a way that one is placed inverted with respect to the other and a narrow beam of white light is incident on one, it emerges out of the second prism as white light. Angle of deflections of the two prisms are equal and opposite. While the first prism splits the light in the seven colours due to different angles of deflection, the second prism combines the spectrum along a single ray and the colours again combine to give white light as the emergent light.