Question

A tuning fork A, marked 512 Hz, produces 5 beats per second, when sounded with another unmarked tuning fork B. If B is loaded with wax the number of beats is again 5 per second. What is the frequency of the tuning fork B when not loaded?

Answer 1

Frequency of tuning fork A,

v_A = 512 Hz

Now, frequency of tuning fork B may be-

V_B = v_A ± 5 = 512 ± 5 = 517 or 507 Hz

As on loading B, frequency decreases

If v_B = 517 Hz, if might reduced to 507 Hz, given again a beat of 5 Hz.

If v_B = 507 Hz, reduction will always increase the frequency of beat, so, V_B = 517 Hz