A parallel beam of light of wavelength 6000 Å gets diffracted by a single slit of width 0.3 mm.The angular position of the first minima of diffracted light is

Options

A. `2xx10^(-3)` rad
B. `3xx10^(-3)`rad
C. `1.8xx10^(-3)` rad
D. `6xx10^(-3)` rad

Answer

A

Explanation

Here,`lambda=6000Å=6000x10^(-10)m=6xx10^(-7)m`
a=0.3 mm`=0.3xx10^(-3) m=3xx10^(-4)m`
For first minima
`asintheta=lambda` Where a is the slit width
`Sintheta=(lambda)/(a)=(6xx10^(-7)m)/(3xx10^(-4)m)=2xx10^(-3)`
As `sintheta` is very small
`therefore theta=sintheta=2xx10^(-3)`rad