Parallel light of wavelength 5000 Å falls normally on a single slit. The central maximum spreads out to `30^(@)` on either side of the incident light.Find the width of the slit.For what width of the slit the central maximum would spread out to `90^(@)` from the direction of the incident light ?

Explanation

The direction of first minima is given by the relation
`asintheta_(1)=lambda`
Therefore, the slit width
`a=(lambda)/(sintheta_(1))=(589xx10^(-9)m)/(sin0.22^(@))= 1.53 xx 10^(-4) m`