In Young's double slit experiment intensity at a point is `((1)/(4))` of the maximum intersity. Angular position of this point is

Options

A. `sin^(-1)((lambda)/(d))`
B. `sin^(-1)((lambda)/(2d))`
C. `sin^(-1)((lamda)/(3d))`
D. `sin^(-1)((lamda)/(4d))`

Answer

C

Explanation

`I=I_maxcos^2(pidsintheta)/(lamda)`
`implies(I_(max)/(4)=I_(max)cos^(2)((pidsintheta)/(lamda))`
`:'cos(pidsintheta)/(lamda)=(1)/(2)`:' (pidsintheta)/(lamda)=(pi)/(3)`
`:' theta=sin^(-1)((lamda)/(3d))`