Question #0c3b8

1 Answer
Feb 26, 2017

θred should be greater than angle θblue - see below.

Explanation:

We know for the grating that:

dsinθ=nλ, see below for meaning of terms in this equation.

For constant slit width d and looking just at the first maximum at n=1, we see that for angle θ to normal:

θ=arcsin(λd)

If we use the following wavelengths, ie λ's, as being indicative:

  • λred=650nm

  • λblue=475nm

.... then it follows that angle θred should be greater than angle θblue.