Q. 32

The line-width of a bright fringe is sometimes defined as the separation between the points on the two sides of the central line where the intensity falls to half the maximum. Find the line-width of a bright fringe in a Young’s double slit experiment in terms of λ. d and D where the symbols have their usual meanings.

Answer :

Given, separation between the slits

The distance between the screen and the slit,


Wavelength of light, .


Let the maximum intensity be and the intensity at y be .


Given,








therefore, path difference,



But the fringe extends to both sides of the maximum. Hence, the line width is



Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
RELATED QUESTIONS :