Question

On sounding tuning fork a with another tuning fork b of frequency 384hz 6 beats are produced per second.After loading the prongs of a with wax and then sounding it again with b,4 beats are produced per second what is the frequency of the tuning fork a

Answer 1

Answer:

390

Explanation:

A beat per second is equivalent to a cycle per second i.e the number of beats per second is equal to the difference in frequency.

If B is 384 hz, then A could be either 378 hz or 390 hz because beats are 6 when not waxed.

When we slow A down by adding extra mass, then the  beats will also decrease. Now addition of mass they are closer to in-tune. Therefore A was originally at 390 hz. (If it had been 378 hz, adding mass would have increased the beats to 8, rather than decreasing them to 4.)