Question

A piano tuner using a 264 Hz tuning fork hears 6beats per second while playing the tuning fork and a piano key at the same time. If the tuner switches to a 268 Hz tuningfork, what are the possible beatfrequencies that could be detected? (A). only 2Hz (B). only 10Hz. (C). only 8Hz. (D). 2Hz and 8Hz. (E). 2 Hz and10Hz. Explain, please!

Answer 1

number of beats is defined as the difference in frequencies.

in the given situation, there may be 2 cases as following

i] frequency of piano is higher than that of tuning fork.

ii] frequency of piano is lower than that of tuning fork

in the first case, difference of frequencies will decrease as frequency of tuning fork is increased from 264 to 268.

i.e. beats will decrease to 6-4=2 Hz

in the second case, difference of frequencies will increase as frequency of tuning fork is increased from 264 to 268.

i.e. beats will increase to 6+4=10 Hz

hence option (E). 2 Hz and 10 Hz is correct.