In Young's double slit experiment, how many maximas can be obtained on a screen (including the central maximum) on both sides of the central fringe if `lambda=2000 Å` and `d= 7000 Å` ?

Explanation

For maximum intensity on the screen `d sin theta = n lambda ` or
`sin theta = (n lambda)/(d)` ,
`= ((n)(2000))/((7000)) = (n)/(3.5)`
Maximum value of sin `theta = 1`
`:. n = - 3, - 2, - 1, 0, 1, 2, 3, :. 7` maximas