Optics Question 224
Question: Direction of the first secondary maximum in the Fraunhofer diffraction pattern at a single slit is given by (a is the width of the slit)
[KCET 1999]
Options:
A) $ a\sin \theta =\frac{\lambda }{2} $
B) $ a\cos \theta =\frac{3\lambda }{2} $
C) $ a\sin \theta =\lambda $
D) $ a\sin \theta =\frac{3\lambda }{2} $
Show Answer
Answer:
Correct Answer: D
Solution:
For nth secondary maxima path difference $ d\sin \theta =(2n+1)\frac{\lambda }{2} $
$ \Rightarrow $ $ a\sin \theta =\frac{3\lambda }{2} $
