In a YDSE, D = 1m, d = 1mm and `lambda = 1//2 mm`
Find a distance between the first and central maxima on the screen.

Explanation

`D gt gt d`
Hence `Delta P = d sin theta`
`(d)/(lambda)=2`,
clearly, `n lt lt (d)/(lambda)=2` is not possible for any value of n.
Hence `Delta p = (dy)/(D)` cannot be used
For Ist maxima,
`Delta p = d sin theta = lambda`
`rArr sin theta = (lambda)/(d)=(1)/(2)`
`rArr theta = 30^(@)`
Hence, `y = D tan theta = (1)/(sqrt(3))` meter