Question

3. What color of laser light shines through a diffraction grating with a line density of 500 lines/mm if the third maxima from the central maxima (m=3) is at an angle of 45°?

Answer 1

Wavelength is 471 nm

Step-by-step explanation:

Given that,

Lines per unit length of diffraction grating is 500 lines/mm.

The third maxima from the central maxima (m=3) is at an angle of 45°

We need to find the color of laser light shines through a diffraction grating.

The condition for maxima is :

`d\sin\theta=m\lambda`

d = 1/N, N = number of lines per mm

`\lambda=(1)/(Nm)\sin\theta\\\\\lambda=(10^(-3))/(500* 3)\sin(45)\\\\\lambda=4.31* 10^(-7)\\\\\text{or}\\\\\lambda=471\ nm`