- #1
Shahab Mirza
- 28
- 0
Hi,
1. Homework Statement
Q : A diffraction grating with 10000 lines per CM is illuminated by yellow light of wavelength 589 nm, At what angles is the 2nd order bright fringes seen ?
From my textbook , I got this equation , d sin theta = m (λ)
Ok so what I did was that I plugged values properly , i.e
sin theta = mλ/d
For second order , m=2 so,
= (2) (589 X 10nm) / (1/10000 X 1/ 100)
and the answer is 1.178 , but out teacher said that this number is larger than 1 and so sin theta does not represent any rational angle , so tell me that how to know that sin theta in this case "1.178" does not represent any rational number , please help me out with this , Thanks [/B]
1. Homework Statement
Q : A diffraction grating with 10000 lines per CM is illuminated by yellow light of wavelength 589 nm, At what angles is the 2nd order bright fringes seen ?
Homework Equations
From my textbook , I got this equation , d sin theta = m (λ)
The Attempt at a Solution
Ok so what I did was that I plugged values properly , i.e
sin theta = mλ/d
For second order , m=2 so,
= (2) (589 X 10nm) / (1/10000 X 1/ 100)
and the answer is 1.178 , but out teacher said that this number is larger than 1 and so sin theta does not represent any rational angle , so tell me that how to know that sin theta in this case "1.178" does not represent any rational number , please help me out with this , Thanks [/B]