Optics Question 167
In a single slit diffraction of light of wavelength λ by a slit of width a, the size of the central maximum on a screen at a distance D is
Options:
A) $ 2b\lambda + e $
B) $ \frac{2b\lambda }{e} $
C) $ \frac{2b\lambda }{e}+e $
D) $ \frac{2b\lambda }{e}-e $
Show Answer
Answer:
Correct Answer: C
Solution:
The direction in which the first minima occurs is $ \theta $ (say). Then $ e\sin \theta =\lambda $ or $ e\sin \theta =\lambda $ or, $ \theta =\frac{\lambda }{e\sin \theta} $
$ (\because \theta \approx \sin \theta $ when $ \theta $ small) Width of the central maximum $ =2b\theta +e=2b.\frac{\lambda }{e}+e $
BETA
