A parallel beam of light of wavelength 500nm falls on a narrow slit and resulting diffraction pattern is observed on a screen 1m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.

Explanation

Given `1=5xx10^(-7)m , D=1m, x=2.5xx10^(-3) `
w.k.t for DI, `x=(n lambda D)/(x)=(5xx10^(-7)xx1)/(2.5xx10^(-3))=2.0xx10^(-4) m `