Question

Explain the meaning of the term interference.

Short answer

Answer: Interference is the phenomenon where two or more waves superimpose to produce a resultant wave with a changed amplitude. Constructive interference occurs when waves are "in phase," meaning their crests and troughs align, resulting in a higher amplitude. Destructive interference occurs when waves are "out of phase," meaning the crest of one wave aligns with the trough of another, resulting in a lower amplitude or canceling each other out.

Step-by-step solution

Definition of Interference

Interference refers to the phenomenon in which two or more waves superimpose to produce a resultant wave of greater, lower, or the same amplitude. It occurs when waves from different sources combine to produce a combined effect. Interference can be either constructive, resulting in an increased amplitude, or destructive, resulting in a decreased amplitude.

Constructive Interference

Constructive interference happens when two or more waves meet in such a way that their crests line up together, as well as their troughs. This causes the resultant wave to have a higher amplitude than the individual waves. In other words, the waves are said to be "in phase" with each other. For example, consider two waves with the same amplitude and frequency traveling in the same direction along a rope. If these waves meet at a certain point, their combined amplitude will be the sum of the individual amplitudes (i.e., twice the amplitude of either wave).

Destructive Interference

Destructive interference occurs when two or more waves meet in such a way that the crest of one wave coincides with the trough of another wave. This results in the waves canceling each other out, producing a combined wave with a lower amplitude. In other words, the waves are said to be "out of phase" with each other. For example, consider the same two waves from the previous example, but this time the crest of one wave meets the trough of the other wave. In this case, the combined amplitude of the resultant wave is the difference between the individual amplitudes (i.e., potentially zero, if both waves have equal amplitudes). In summary, interference refers to the phenomenon in which two or more waves combine to produce a resultant wave with a changed amplitude. The outcome can be either constructive or destructive, depending on the alignment of the waves' crests and troughs.