#### 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: Option 1) 1 : 2 Option 2) 2 : 1 Option 3) 4 : 1 Option 4) 1 : 1

Maximum amplitude & Intensity -

When

- wherein

Interference occur only in case of coherent source

In case of incoherent source there is no interference and hence intensity at point is 2 i.

Ratio = 2:1

Option 1)

1 : 2

Incorrect

Option 2)

2 : 1

Correct

Option 3)

4 : 1

Incorrect

Option 4)

1 : 1

Incorrect