In a double-slit experiment, the slits are separated by a distance d and the screen is at a distance D from the slits. If a maximum is formed just opposite to each slit, then what is the order or the fringe so formed?

Options

A. `(d^(2))/(2 lambda D)`
B. `(d)/(2 lambda D)`
C. `(d^(2))/(4 lambda D)`
D. 0

Answer

a

Explanation

As a bright fringe is formed in front of slit, therefore
`d//2 =` integral multiple of fringe width
`(d)/(2) = (n lambda D)/(d) implies n = (d^(2))/(2 lambda D)`.