Question

There are two tuning forks 'A and B’, each of frequency \[512\,Hz\]. Thread is wound over one of the prongs of ‘A’. Both the tuning forks are excited simultaneously. A peculiarity in the sound is observed. What do you call this phenomenon?

Answer 1

Hint: As there are two different sources of sound, so interference of sound occurs. The time interval between two successive beats is called beat period and the number of beats produced per second is called the beat frequency.

Complete step by step answer:
It is given that both the tuning forks are operating at the same frequency and. When a thread is wound on one of the fork, interference of sound takes place and the alternating constructive and destructive interference occur. It causes the sound to be alternatively soft and loud. This phenomenon is known as the beat formation. Beats are produced by the interference of waves. When two sound waves of slightly different frequencies travel in a medium along the same direction superimpose on each other, the intensity of the resultant sound at a particular position rises and falls regularly with time. When two sounds of slightly different frequencies are perceived at the same time, we hear a variation in volume whose rate is periodic and is equal to the difference of the two frequencies. The phenomenon of beats is used in tuning the musical instruments.

Note:
Beats are the periodic and repeating variations heard in the intensity of a sound when two sound waves of same frequencies interfere with each other. In beats, frequency of resultant wave is the average of the frequencies of the two component waves.