Superposition

Question 1

Principle of superposition

Answer 1

Principle of superposition states that when two or more waves of the same kind meet at a point, the resultant displacement of the waves at any point is the vector sum of the displacement due to each wave acting independently.

Question 2

Phase difference

Answer 2

Phase difference is an angular measure of the fraction of a cycle two particles in a wave or two waves are out of step.

Question 3

Coherence

Answer 3

Two sources are said to be coherent if waves from each source have a constant phase difference between them

Question 4

Interference

Answer 4

Interference refers to the results of the superposition of two or more waves of the same kind.

Question 5

Constructive interference

Answer 5

Constructive interference occurs when two or more waves meet in phase and superpose to produce a resultant wave of maximum amplitude

Question 6

Destructive interference

Answer 6

Destructive interference occurs when two or more waves meet anti-phase (or 180° out of phase) and superpose to produce a resultant wave of zero or minimum amplitude

Question 7

Path difference

Answer 7

Path difference is the difference in the distance travelled by two waves from their respective coherent wave sources to a point.

Question 8

Diffraction

Answer 8

Diffraction is the spreading of waves around an obstacle or through a gap, into its geometrical shadow.

Question 9

Conditions for observable interference pattern

Answer 9

1. The waves must be of the same kind and superpose at a point.
2. The waves must be coherent.
3. The waves must have about the same amplitude.