Which phenomenon occurs when the rarefactions of one wave align with the compressions of another, causing the waves to cancel?

Which phenomenon occurs when the rarefactions of one wave align with the compressions of another, causing the waves to cancel?

• A. Constructive interference
• B. Destructive interference
• C. Refraction
• D. Reflection

Answer: (B)

When waves meet, they superpose and their effects add together. If a region of high pressure (a compression) from one wave lines up with a region of low pressure (a rarefaction) from the other, the two effects oppose each other. This opposite-phase overlap reduces the overall displacement, and if the two have equal strength, they cancel completely. That’s destructive interference. By contrast, constructive interference happens when compressions align with compressions and rarefactions align with rarefactions, boosting the amplitude. Refraction and reflection involve changes in direction or boundary interactions, not cancellation of overlapping waves.

When waves meet, they superpose and their effects add together. If a region of high pressure (a compression) from one wave lines up with a region of low pressure (a rarefaction) from the other, the two effects oppose each other. This opposite-phase overlap reduces the overall displacement, and if the two have equal strength, they cancel completely. That’s destructive interference. By contrast, constructive interference happens when compressions align with compressions and rarefactions align with rarefactions, boosting the amplitude. Refraction and reflection involve changes in direction or boundary interactions, not cancellation of overlapping waves.