Question
Physics Question on Wave optics
Interference was observed in a chamber when air was present. Now, the chamber is evacuated and if the same light is used, a careful observation will show
A
no interference
B
interference with bright bands
C
interference with dark bands
D
interference in which breadth of the fringe will be slightly increased
Answer
interference in which breadth of the fringe will be slightly increased
Explanation
Solution
As the chamber is evacuated the wavelength of the light increases slightly. Thus as the fringe width is directly proportional to wavelength the fringe width increases.