Monochromatic light passes through two parallel narrow slits and forms an interference pattern on a screen. as the distance between the two slits is decreased, the distance between light bands in the pattern on the screen will
a. decrease.
b. increase.
c. remain the same.

b.increase.

Explanation:

The distance between the light bands and the distance between the two slits, are related as follows:

Here, y is the distance between light bands in the pattern, m is the number of light bands observed in the pattern, is the light's wavelenght, D is the distance between the two slits and the screen where the pattern is observed and d is the distance between the two slits. Thus, as the distance between the two slits is decreased, the distance between light bands will increase.

d) physical means can be used to separate the components of air.