Diffraction Grating

Question 1

Describe diffraction grating.

Answer 1

A diffraction grating is made up of many lines.
The number of lines per unit length are denoted by the letter N. The relationship between N and the width of two adjacent lines, d is N = 1/d
The formula is:
d sin theta = n lambda
n - the number of order
lambda - wavelength
theta - angle between n = 0 and the nth order
d = 1/N

To find the maximum order for a given diffraction grating we substitute theta = 90 into the equation.
Always round down.

Question 2

What are the differences between Young’s Double-Slit Experiment and Diffraction Grating?

Answer 2

Diffraction grating dots are brighter (more light can pass through due to more lines)
Double-slit dots are evenly spread, diffraction grating dots aren’t.