Question

A light wave of wavelength λ is incident on a slit of width d. The resulting diffraction pattern is observed on a screen at a distance D. If linear width of the principal maxima is equal to the width of the slit, then the distance D is

Options

• `(2lambda)/"d"`

• `"d"^2/(2lambda)`

• `(2lambda)^2/"d"`

• `"d"/lambda`

Answer 1

`"d"^2/(2lambda)`

Explanation:

The linear width of the principal maxima,

`beta = (2"D"lambda)/"d"`

It is given that, linear width of the principal maxima is equal to width of slit.

∴ d = `(2"D"lambda)/"d" => "D" = "d"^2/(2lambda)`