Optics Question 1025
Question: Interference was observed in interference chamber when air was present, now the chamber is evacuated and if the same light is used, a careful observer will see
[CBSE PMT 1993; DPMT 2000; BHU 2002]
Options:
A) No interference
B) Interference with bright bands
C) Interference with dark bands
D) Interference in which width of the fringe will be slightly increased
Show Answer
Answer:
Correct Answer: D
Solution:
The refractive index of air is slightly more than 1. When chamber is evacuated, refractive index decreases and hence the wavelength increases and fringe width also increases.
