Physics - Sound Wave Question with Solution | TestHub
Identify the CORRECT statement on beats
(A) The amplitude of beats is always constant.
(B) Beats are produced when two waves have the same frequency.
(C) Beat frequency is the average of the two source frequencies.
(D) Beats can be produced by the waves having slightly different frequencies and traveling in the opposite directions.
Options:
Answer:
Solution:
Beats are produced by the superposition of two waves having slightly different frequencies. The beat frequency is equal to the difference between the frequencies of the two waves, i.e., .
The amplitude of the resultant wave in a beat pattern varies periodically with time, so it is not constant.
When two waves of slightly different frequencies travel in opposite directions, their superposition at any fixed point in space results in an amplitude that varies periodically with time. This periodic variation in intensity is perceived as beats. Therefore, beats can be produced by waves traveling in opposite directions as long as their frequencies are slightly different.
Answer: (D)
