Light from two coherent sources of the same amplitude A and wavelength `lambda` illuminates the screen. The intensity of the central maximum is `I_(0)`. If the sources were incoherent, the intensity at the same point will be

Options

A. `4I_(0)`
B. `2I_(0)`
C. `I_(0)`
D. `I_(0)//2`

Answer

D

Explanation

For two coherent sources, `I_(1)=I_(2)`
`I_(max)=(A_(1)+A_(2))^(2)=(sqrt(I_(1))+sqrt(I_(2)))^(2)`
`I_(max)=I_(0)andI_(min)=0`
For incoherent sources `I=(I_(0))/(2)`.