Chapter 19, Problem 41A

To determine

To Explain: The reason for diffraction gratings to have large number of slits and the slits are close together.

Explanation of Solution

Introduction:

Diffraction is a phenomenon wherein light bends at the corners of an obstacle in its path and enters the shadow region.

For diffraction to take place, the size of the obstacle must be equivalent to the wavelength of the light.

The diffraction gratings have large number of slits which are closed to together to meet the condition for diffraction to occur.