An adjustable sound source produces 2 beats per second with a tuning fork when the source frequency is either 476 Hz or 480 Hz. Find the tuning-fork frequency.
Physics · Wave Motion
JEE Mains Advanced

Question

An adjustable sound source produces 2 beats per second with a tuning fork when the source frequency is either 476 Hz or 480 Hz. Find the tuning-fork frequency.

G1 Physics · Accepted Answer

Step 1: A 2 Hz beat occurs when the adjustable source is 2 Hz above or below the fork. Step 2: The two observed source settings 476 Hz and 480 Hz are symmetric about the fork frequency. Therefore f = (476+480)/2 = 478 Hz.