Question

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

Answer 1

well, in the first case the valleys and mountains align, so the intensity should be less than the double, depending on the phase shift of the sources.