- #1
aurao2003
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Homework Statement
Hi
A liitle help will be appreciated. The question is as follows:
A laser beam of wavelength 630nm is directed normally at a diffraction grating with 300 lines per millimetre. Calculate:
a) The angle of diffraction of each of the first 2 orders
b) The number of diffracted orders produced
Homework Equations
I used the formula
d X sintheta = n x wavelength
The Attempt at a Solution
N= 300000
therefore d= 1/300000
n=2
Wavelength = 630nm
Putting the above value in I obtained 22 .2 degrees
b) For the second part, I surmised that theta = 90 degrees
Therefore,
n = d/wavelength
I obtained 5. 29. But this diifers from the books answer.
Please help!