# Homework Help: Range of wavelength from white light through a diffraction grating

1. Mar 24, 2010

### FLCL

1. The problem statement, all variables and given/known data

A narrow beam of collimated white light falls at normal incidence upon a transmission grating with 3150 lines per cm. A spectrum is formed by the grating on a screen 30 cm away. If a 1 cm square hole is cut in the screen its inner edge being 5 cm from the zeroth order, what range of visible wavelengths passes through the hole?

2. Relevant equations

N$$\lambda$$ = dsin$$\theta$$

3. The attempt at a solution

$$\frac{\Delta\lambda}{\theta\Delta}$$ = $$\frac{d}{N}$$$$\sqrt{1 - sin^2\theta}$$

2. Mar 25, 2010

### ehild

What is the range of angle determined by the square hole ?

ehild