In Young's double slit experiment, phase difference between the waves at a point on screen having intensity less than the average intensity on screen may be

Options

A. `pi//4`
B. `2pi//3`
C. `pi`
D. `7pi//8`

Answer

B, C, D

Explanation

Let maximum intensity be `I_(0)`
`I=I_(0)omegat(Deltaphi)/2`
`I_(av)=I_(0)/2`
`I lt I_(av) Rightarrow"cos"^(2)((Deltaphi)/2) lt1/2`
`Rightarrow"cos" ((Deltaphi)/2) lt 1/sqrt(2)`
`Rightarrow pi/2 lt Deltaphi lt (3pi)/2`