With a neat labelled diagram, describe the experiment to demonstrate dispersion of sunlight ( white light ) by a prism.

Explanation

Experiment :
(1) Procedure: Keep a glass prism on a table in a dark room. Hold a plane mirror outside the room so that it reflects a beam of sunlight into the room. Allow this beam to pass through a narrow slit made in a cardboard and then fall on the prism. Place a white screen on the other side of the prism as shown in the following figure.
(ii) Observations :
(1) A pattern of various colours is observed on the screen. This pattern is called the spectrum.
(2) It is found that in disperion, the ray corresponding to violet, colour deviates the most.
(3) The ray corresponding to red colour deviates the least.
(4) Conclusion : When sunlight (white light) is incident on a prism, dispersion of light takes place, forming a spectrum.
(iii) Conclusion : When sunlight (white light) is incident on a prism, dispersion of light takes place, forming a spectrum.