Question

If the frequencies of two component waves are 24 Hz and 20 Hz, they should produce _______ beats per second.

A. 2
B. 4
C. 8
D. 12

Answer 1

They produce two "beat" waves.
One beat is at 44 Hz.
The other one is at 4 Hz.

Answer 2

B. 4

Step-by-step explanation:

Beat frequency (fb) is calculated as follows:

fb = |f1 - f2|

where f1 and f2 are two sounds frequencies, in this case, 24 Hz and 20 Hz. Replacing in the equation:

fb = |24 - 20| = 4 Hz

Then, they should produce they 4 beats per second