Question

The distance between the first and ninth bright fringes formed in a biprism experiment is ______.

(`lambda` = 6000 A, D = 1.0 m, d = 1.2 mm)

Options

• 0.004 m

• 0.04 m

• 4 x 10^-4 m

• 0.4 m

Answer 1

The distance between the first and ninth bright fringes formed in a biprism experiment is 0.004 m.

Explanation:

The fringe width between fir t and seventh bright fringes is

`"w"=(9-1) (lambda "D")/"d"`

`=8xx (6000xx10^-10)/(1.2xx10^-3)xx1.0`

=0.004 m