<h2>The frequency of tuning fork B is 475 Hz</h2>
Explanation:
The number of beats produced is equal to the frequency difference between the two tuning forks .
The frequency of A = 480 Hz
Thus the frequency of B can be = 485 or 475 Hz
When B is filed , its frequency increases and it start producing 2 beats with A .
Thus it frequency must be 475 Hz , by filing , it increases to 478 Hz .
By which it gives 480 - 478 = 2 beats per second .
This cannot happen with frequency 485 , because by filing this difference increases in place of decreasing .
