In deriving the single slit diffraction pattern, it was stated that the intensity is zero at angles of nλ/a. Justify this by suitably dividing the slit to bring out the cancellation.
Consider that a single slit of width d is divided into n smaller slits.
∴Width of each slit, `d' = d/n`
Angle of diffraction is given by the relation,
`theta = (d/d lambda)/d = lambda/d`
Now, each of these infinitesimally small slit sends zero intensity in directionθ. Hence, the combination of these slits will give zero intensity.