When two waves from coherent sources move in the same region of space they overlap leading to interference of the waves. Depending on whether the waves are in phase or out of phase it results in two types of interference; Constructive and destructive interference.

1. CONSTRUCTIVE INTERFERENCE

This occurs when the two waves reinforce each other’s effect; such that the resultant wave is a larger wave which has larger amplitude than the two waves.

This mainly occurs when a crest of one wave superimposes on another crest from a second wave or when a trough one wave superimpose with another wave in case of a transverse wave.

In case of a longitudinal wave it occurs when one compression combine with another from the second wave or a rarefaction form one wave combine with a rarefaction from a second wave.

1. DESTRUCTIVE INTERFERENCE

This occurs when the waves superimpose on each other and cancel each other’s effect.

The resultant is that we either obtain a smaller wave with small amplitude or no wave at all.

This occurs when a trough from one wave coincides with a crest from the second wave in case of a transverse wave or a compression from one wave superimpose with a rarefaction from the second wave in case of a longitudinal wave.

The following conditions must be satisfied for a wave to undergo interference;

• The waves must be from a coherent source (having the same characteristics).
• They must be traveling in the same region of space.

Define the term interference as used in waves and state the conditions for interference to occur.

Differentiate between constructive and destructive interference..