Question

Direction of the first secondary maximum in the fraunhoffer diffraction pattern at a single slit is given by:

• A. a sin $\theta =\frac{\lambda }{2}$
• B. a sin $\theta =\frac{3\lambda }{2}$
• C. acos $\theta =\frac{3\lambda }{2}$
• D. a sin $\theta =\lambda$

Answer 1

The correct option is A a sin $\theta =\frac{\lambda }{2}$

location for fraunhoffer diffraction is given by:- $a$ $sin$$\theta$=(2n-1)$\frac{\lambda }{2}$

for secondary maxima the first secondary maxima is obtained when $n=1$

$asin$$\theta$

=$\frac{\lambda }{2}$