Two tuning forks A and B produce 10 beats per second when sounded together. On slightly loading fork A with a little wax, it was observed that 15 beats are heard per second. If the frequency of fork B is 480 Hz, what is the frequency of fork A before it was loaded?


Correct option is

470 Hz


Let V1 be the frequency of A and V2 that of fork B. There are two possibilities (a) V1 > V2 and (b) V1 < V2.   

On loading fork A its frequency decreases. In order words, V1 decreases. 

 should also decrease. But Vb increase to 15 beats/s. Hence V1 is not greater than V2.   




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