Two coherent sources of light can be obtained by: A)Two different lamps of the same power B)Two different lamps C)By dividing wavefront D)Two different lamps of the different power

Answer: Option (C) By dividing a wavefront 

Explanation: Two coherent wave lights are perfectly coherent if their frequency and waveform are the same and the phase difference is constant. Two coherent sources cannot be obtained from two different sources of light.