Question

What happens to the interference pattern if the two slits in Young's experiment are illuminated by two independent sources such as two sodium lamps $S$ and $S^{\prime }$ as shown in figure.

• A. Two sets of interference fringes overlap.
• B. No fringes are observed.
• C. The intensity of the bright fringes is doubled.
• D. The intensity of the bright fringes becomes four times.

Answer 1

The correct option is B No fringes are observed.

No interference pattern i.e., no fringes would be observed because the two sources are non-coherent.