Visible light passes through a diffraction grating that bas 900 slits/cm, and the interference pattern is observed on a screen that is 2.50 m from the grating.
(a) Is the angular position of the first-order spectrum small enough for sin θ ≈ θ to be a good approximation?
(b) In the first-order spectrum, the maxima for two different wavelengths are separated on the screen by 3.00mm.
What is the difference in these wavelengths?