White light (light containing all frequencies of light in the visible spectrum) passes through a diffraction grating with 1300 lines per centimeter, and a screen is placed 2 meters away. what is the distance between the 1st order blue fringe and the 1st order red fringe? (for red light use red- 700 nm and for blue light use ablue 450 nm).

The distance between the 1st order blue fringe and the 1st order red fringe is 6.5 cm.

Explanation:

Given that,

Diffraction grating =1300 lines/cm

Distance of screen = 2 m

Order number = 1

We need to calculate the distance between the 1st order blue fringe and the 1st order red fringe

Using formula of distance

For first order red fringe

For first order blue fringe

We need to calculate the distance between blue fringe and red fringe

Hence, The distance between the 1st order blue fringe and the 1st order red fringe is 6.5 cm.