Question

Red light of wavelength 633 nm from a helium-neon laser passes through a slit 0.400 mm wide. The diffraction pattern is observed on a screen 3.10 m away. Define the width of a bright fringe as the distance between the minima on either side.

Answer 1

`x=4.906nm`

Step-by-step explanation:

Data

wavelength: ∧=
`633nm`
`∧=0.633um`

slit: a=
`0.400mm`
`a= 400mm`

`R=3.10m`

To find tita(angle):

sin(Tita)=∧/a

`sin(tita)=(0.633um)/(400um) \\sin(Tita)=0.0015825\\Tita=sin^(-1) (0.0015825)`

Tita=0.09°

distance between the minima on either side:

`x=R*tan(Tita)\\x=(3.10m)*tan(0.09)\\x=3.10m*0.0015825\\x=0.004906m\\x=4.906nm`