Coherent light from a sodium-vapour lamp is passed through a filter that blocks everything except for light of a single wavelength. It then falls on two slits separated by 0.460 mm. In the resulting interference pattern on a screen 2.20m away, adjacent bright fringes are separated by 2.82 mm. What is the wavelength ?

Explanation

`because Omega = (lambdaD)/d`
`:. lambda = (omegad)/D = ((2.82 xx 10^-3)(0.46 xx 10^-3))/2.2 `
` = 0.589 xx 10^(6)` m
` ~~0.590nm`