At the first minimum adjacent to the central maximum of a single-slit diffraction pattern the phase difference between the Huygens wavelet from the edge of the slit and the wavelet from the mid-point of the slit is

Options

A. `(pi)/(2)` radian
B. `pi` radian
C. `(pi)/(8)` radian
D. `(pi)/(4)` radian

Answer

B

Explanation

For 1st minima
Path difference = `asintheta= lambda`
From mid point, path difference= `lambda//2`
`:. ` Phase difference = `(2pi)/(lambda) xx (lambda)/(2)= pi`