Question

When a tuning fork A of unknown frequency is sounded with another tuning fork B of frequency 256 Hz, 3 beats per second are observed. After that A is loaded with wax and sounded, the beat frequency decreases. Find the frequency of the tuning fork A.

Answer 1

The frequency of the fork B can be 

= 256 ± 3  Hz 

= 259 Hz or 253 Hz 

Suppose the frequency of the fork B 

= 259 Hz 

On loading, its frequency let becomes 

= 257 Hz. 

Now it will give less number of beats with the fork B. So the frequency of fork A must be 259 Hz.