Question

• If we use two sodium lamps illuminating two pinholes, then we will not observe any interference fringes.

• WHY SO .?

Answer 1

Dear Student,

Two independent sources of light cannot be used to get interference pattern. This is because of the following two reasons,

1. Two independent sources of light cannot emit light waves continuesly,

2. The phase difference will not be same or constant between the waves emitted by two independent sources of light.

This is the reason we cannot use two sodium lamps to illuminate two pin holes to get interference pattern.