Central Fringe and Medium Effect – Rankers Physics
Topic: Wave Optics
Subtopic: Young's Double Slit Experiment

Central Fringe and Medium Effect

Assertion (A): The central fringe is bright or dark, it depends on the initial phase difference between the two coherent sources.
Reason (R): The pattern and position of fringes always remains same even after the introduction of transparent medium in a path of one of the slit.
 
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Solution:

The central fringe's nature (bright/dark) depends on the initial phase difference. Introducing a transparent medium with refractive index \(n\) and thickness \(t\) in one path creates an additional path difference \((n-1)t\), shifting the entire fringe pattern. So, (R) is false.

Leave a Reply

Your email address will not be published. Required fields are marked *