The direction of the first secondary maximum in the fraunhoffer diffraction pattern at a single slit is given by (a is the width of the slit)

Options

A. `asintheta=(lamda)/(2)`
B. `acostheta=(3lamda)/(2)`
C. `asintheta=lamda`
D. `asintheta=(3lamda)/(2)`

Answer

D

Explanation

The direction of the nth secondary maximum is given by `asintheta=(2n+1)(lamda)/(2)`
for `n=1,asintheta=(3lamda)/(2)`.