# Fringe with of interference pattern

1. Jan 28, 2008

### looi76

1. The problem statement, all variables and given/known data
Calculate the fringe width of an interference pattern created by two coherent source, 1mm apart and emitting light of wavelength 600 nm. the pattern is observed on a screen 50cm from the source

2. Relevant equations
x = dλ/a

3. The attempt at a solution
I don't know how to start...

Last edited: Jan 28, 2008
2. Jan 28, 2008

### Hootenanny

Staff Emeritus
Well you must have some idea since you know the equation.

3. Jan 28, 2008

### looi76

λ = wavelength, can you tell me what does x, d and a represent.

4. Jan 28, 2008

### Hootenanny

Staff Emeritus
x represents the width of the fringe, d represents the distance between the slits and the screen; and a represents the slit separation. Surely you have a textbook and/or class notes?

5. Jan 28, 2008

### looi76

Thanks Hootenanny... I think I got it...

d = 50cm , a = 1mm , λ = 600nm

d = 50*10^-2m
a = 1*10^-3m
λ = 600*10^-9m

= (600*10^-9*50*10^-2)/(1*10^-3)
= 3*10^-4m

6. Jan 28, 2008

### Hootenanny

Staff Emeritus
Looks good to me