Optics Question 894
Question: In an experiment of single slit diffraction pattern, first minimum for red light coincides with first maximum of some other wavelength. If wavelength of red light is 6600 A, then wavelength of first maximum will be:
Options:
A) $ ~3300\overset{o}{\mathop{A}} $
B) $ 4400\overset{o}{\mathop{A}} $
C) $ 5500\overset{o}{\mathop{A}} $
D) $ 6600\overset{o}{\mathop{A}} $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] In a single slit experiment, For diffraction maxima, $ a\sin \theta =(2n+1)\frac{\lambda }{2} $
and for diffraction minima, $ a\sin \theta =n\lambda $
According to question, $ (2\times 1+1)\frac{\lambda }{2}=1\times 6600 $
$ (\because {\lambda _{R}}=6600\overset{o}{\mathop{A}}) $
$ \lambda =\frac{6600\times 2}{3}=4400\overset{o}{\mathop{A}} $
