Question

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 1

Given :

Separation between two slits = d

Wavelength of the light = λ

Distance of the screen = D

we know that the line width of a bright fringe is sometimes defined as the separation between the point on the two sides of the central line were intensity falls to the maximum.

we know that for intensity to be the half the maximum

y= ± λD/ 4d

Line width = λD/4d + λD/4d

=λD/2d

Answer 2

Explanation:

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