In Young's double-slit experiment, the two slits act as coherent sources of equal amplitude `A` and of wavelength `lamda`. In another experiment with the same set-up the two slits are sources of equal amplitude `A ` and wavelength `lamda`, but are incoherent. The ratio of the intensity of light at the midpoint of the screen in the first case to that in the second case is....

Options

A. `4:1`
B. `2:1`
C. `1:1`
D. Noen of the above

Answer

B

Explanation

`(I _("coherent"))/( I _("noncherent")) = ( 4 I _(0))/( 2 I _(0)) = (2)/(1)`