Two light sources are said to be coherent if they are obtained from

Options

A. Two independent point sources emitting light of the same wavelength
B. A single point source
C. A wide source
D. wo ordinary bulbs emitting light of different wavelengths

Answer

B

Explanation

When two sources are obtained from a straight source, the wavefront is divided into two parts. These two wavefronts acts as if they emanated from two sources having a fixed phase relationship.