Coherent source are sources have same _______ , same _______ and in phase of _______ phase difference.

Constructive interference occurs when of crests or troughs of both waves coincide to produce a wave with crests or troughs of _______ amplitude.

Destructive interference occurs when crest of one wave coincide with the trough of other wave, thus cancelling each other with the result that resultant amplitude is ________ .

Antinode is a point where __________ occurs

_______ is a point where destructive interference occurs.

Electromagnetic wave is a vibration of _______ and _______ at ________ angle.