Question

In biprism experiment, the 4^th dark band is formed opposite to one of the slits. The wavelength of light used is ______.

Options

• `"d"^2/(7"D")`

• `"d"^2/(9"D")`

• `"d"^2/(14"D")`

• `"d"^2/(11"D")`

Answer 1

In biprism experiment, the 4^th dark band is formed opposite to one of the slits. The wavelength of light used is `underline("d"^2/(7"D"))`.

Explanation:

y'₄ = (2n - 1)`(lambda"D")/(2"d") = "d"/2`

`(7lambda"D")/"d"` = d

`therefore lambda = "d"^2/(7"D")`