The intensity pattern formed by a diffraction grating of N slitsis
where θ is the angle of diffraction. The radiation reaches thegrating at normal incidence.
Using the formula above and m = 0, ±1, ±2 ... and p = aninteger ≠mN
- show that
- the interference maxima occur for β = mπ
- and minima occur for  β = pπ/N .
- show that the orders m=pd/a (of interference) are missing ifd/a is an integer .
