 # Destructive Interference

Destructive interference takes place when waves come together in such a manner that they completely cancel each other out. When two waves destructively interfere, they must have the same amplitude in opposite directions.

There are many interesting wave phenomenon in nature, that cannot be defined by an individual wave. To comprehend the destructive interference phenomenon, we must examine based on the combination of waves. To examine these, we apply the principle of superposition which says:

“If two or more waves are traveling in a medium, the resulting wave function is the algebraic total of the individual waves function.”

When the waves of identical frequency and equivalent amplitude superimpose, the process of interference takes place. When two waves of a similar frequency move in a medium at the same time and towards the same direction, because of their superposition, the resulting intensity of the medium at any point is dissimilar from the sum of their intensities. At some points, the strength of the resultant wave bears a larger value, while at certain points the value is very small. In this segment, we will concentrate more on Destructive Interference.

## What is Destructive Interference?

When two waves of similar frequencies travel in a medium, the resultant at different points is dissimilar from the sum of their intensities because of their superposition. At one point it is too less and negligible which we call Destructive Interference. The crest of wave A overlaps with the trough of wave B and vice versa as a result of which they cancel each other out.

In the above figure, A and B are the two waves of similar frequencies travelling in a medium in a similar direction.

You may also want to check out these topics related to the concept of interference given below!

## Destructive Interference Equation

The phase difference among two waves an odd multiple of π that is:

 (2n – 1) π

The difference between the path of two waves is an odd multiple of λ/2,

 Δ = (2n–1) λ/2

The time interval among the two waves is an odd multiple of T/2,

 θ = (2n–1) T/2

The resultant amplitude is equivalent to the difference between the amplitudes of individual waves.

## Examples of Destructive Interference

Some destructive interference examples are given below:

• Gravitational waves are a specimen of Destructive Interference.
• Light beams demonstrate Destructive Interference.
• Moving electrons and radio waves also perform Destructive Interference.

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