# Problem: A commercial diffraction grating has 400 lines per mm. When a student shines a 490 nm laser through this grating, how many bright spots could be seen on a screen behind the grating.

###### FREE Expert Solution

Diffraction:

$\overline{){\mathbf{d}}{\mathbf{s}}{\mathbf{i}}{\mathbf{n}}{\mathbf{\theta }}{\mathbf{=}}{\mathbf{m}}{\mathbf{\lambda }}}$

m is the order while d is the spacing of the grating.

The number of spots for a given order:

θ = 90° for the total number of bright spots.

90% (32 ratings)
###### Problem Details

A commercial diffraction grating has 400 lines per mm. When a student shines a 490 nm laser through this grating, how many bright spots could be seen on a screen behind the grating.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the !! Diffraction Grating concept. If you need more !! Diffraction Grating practice, you can also practice !! Diffraction Grating practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Hailu and Yacoby's class at HARVARD.