Optics Question 464
Question: In Young’s double-slit experiment, the slits are illuminated by monochromatic light. The entire set-up is immersed in pure water. Which of the following act cannot restore the original fringe width?
Options:
A) Bringing the slits close together.
B) Moving the screen away from the slit plane.
C) Replacing the incident light by that of longer wavelength.
D) Introducing a thin transparent slab in front of one of the slits.
Show Answer
Answer:
Correct Answer: D
Solution:
[d] $ {\beta _{w}}=\frac{\lambda D}{\mu d} $ We need to increase $ \beta \Rightarrow D $ increases; d decreases.
