Refraction of wave is a change in the _________ of waves as the waves pass from one medium to another.

Diffraction of wave is a phenomenon in which waves ________ as they pass through a gap or round a small obstacle.

Monochromatic light is a light of _______ colour or of ______ wavelength only.

Principle of superposition states that when two waves move simultaneously and coincide at one point ,the sum of the __________ at that point is equal to the sum of displacements at the individual waves by ________ method.

Interference is the superposition of two waves originating from ______ coherent sources.

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.