The Total solution for NCERT class 6-12
In deriving the single slitdiffraction pattern, it was stated that the intensity is zero at angles of nλ/a. Justify this by suitably dividing theslit to bring out the cancellation.
Consider that a single slit ofwidth d is divided into n smaller slits.
Angle of diffraction is given bythe relation,
Now, each of theseinfinitesimally small slit sends zero intensity in directionθ. Hence, the combination of these slitswill give zero intensity.