- #1
Viviana
- 5
- 0
Homework Statement
Light of wavelength 450 nm is incident normally on a grating with 300 lines per millimeter. How many orders of diffraction maxima can be obtained?
Homework Equations
d sin(theta) = n(lambda)
The Attempt at a Solution
300 lines per millimeter is 3.33 x 10^-6. And 450 nm should be 4.5 x 10^ -7 m.
This is my equation:
3.33 x 10^-6 sin 90 = n (4.5 x 10^ -7)
I get n= 7.4 = 7
The correct answer is 15. But i just can't get this answer. =( Can someone please guide me?