Interference

Question 1

What is the principle of superposition?

Answer 1

When 2 or more waves of the same type meet, the resultant wave can be found by adding the displacements of the individual waves.

Question 2

What is constructive interference?

Answer 2

When 2 waves with the same amplitude exist at the same point and are in phase, the amplitude of the resultant wave will be twice that of the individual wave.

Question 3

What is destructive interference?

Answer 3

If 2 waves are in anti phase , they will cancel each other out and the resultant wave will have an amplitude of 0.

Question 4

What is phase difference?

Answer 4

It is the difference in phase of 2 waves with the same frequency (measured in radians)

Question 5

What is path difference?

Answer 5

The difference in metres between the distances travelled by two waves arriving at the same point.

Question 6

What is coherence?

Answer 6

A fixed relationship between the phase of waves. 2 waves are coherent when the phase difference between is constant.