- #1
Godcanthelp
- 4
- 0
Homework Statement
A five-slit system with 8.4*10-6 slit spacing is illuminated with 610*10-9 light.
Find the angular position of the first two maxima, and the 3rd and 6th minima.
Homework Equations
For Maxima:
d*sin(θ) = m*λ
θ = sin-1((m*λ)/d)
For Minima:
d*sin(θ) = (m/N)λ
θ = sin-1((m/(N*d))λ)
The Attempt at a Solution
λ = 610*10-1
d = 8.4*10-6
N = 5
Subbing my values into find the first and second maxima I solve for θ = 4.16, 8.35 respectively. These answers are correct according to my online module.
However, I cannot find the 3rd and 6th minima.
My attempt:
for m = 3
θ = sin-1((m/N*d)λ)
θ = sin-1((3/(5*8.4*10-6))610*10-9)
θ = 2.49°
for m = 6
θ = sin-1((6/(5*8.4*10-6))610*10-9)
θ = 4.99°
These answers are given as incorrect using the online module.I read further into the problem and discovered that a system with N = 5 slits should have N-1 = 4 minima between each maxima. From the equation we can see that the 3rd minima will occur at 3/5 of one wavelength. Maybe I should try a trigonometric approach?
I am really stuck and any input is greatly appreciated.
Regards