a turning folk when sounded with a folk of frequency 256Hz gave 4 beats/second. when small beat of wax was attached to a prong of the folk of unknown frequency 3 beats/seconds were produced.what is the frequency of unknown

 

The answer should be obvious.

 

Hi mndewa,
The frequency should be either 256+4 or 256-4 which means either 260 or 252. On loading with wax, the frequency will decrease. So the frequency of unknown fork is 252. Hope this helps.

 

If the freq. of unknown decreases with a wax load, then the answer would be 260 Hz.

when loaded the freq of unknown became closer to the standard as in 3 beats vs 4 beats unloaded. Therefore the unknown would be higher.

 

Yes Kermit2 is correct.