Optics Question 234
Question: A single slit of width $ a $ is illuminated by violet light of wavelength 400 nm and the width of the diffraction pattern is measured as y. When half of the slit width is covered and illuminated by yellow light of wavelength 600 nm, the width of the diffraction pattern is
[KCET 2005]
Options:
A) The pattern vanishes and the width is zero
B) y / 3
C) 3y
D) None of these
Show Answer
Answer:
Correct Answer: C
Solution:
In single slit experiment, Width of central maxima (y) = $ 2\lambda D/d $
Therefore $ \frac{y’}{y}=\frac{\lambda ‘}{d’}\times \frac{d}{\lambda }=\frac{600}{d/2}\times \frac{d}{400}\Rightarrow y’=3y $ .
