#
BEATS

38.The natural frequency of a tuning fork P is 432Hz, 3beats are produced when tuning fork Pand another tuning fork Q are sounded together.If P is loaded with wax, the no of beats increases to 5 beats/sec The frequency of Q is --------

**Frequency of beats:**

It is equal to the difference of frequencies of both tuning forks.

Assume that the frequency of tuning fork P is greater than the frequency of tuning fork Q.

**Case I: (without loading with wax)**

P - Q = 3

**Case II: (Tuning fork Q is loaded with wax)**

P - Q' = 5

**On loading the tuning fork, its frequency reduces.**

So, Q' is less than Q.

When Q' is less than Q, then the number of beats (P-Q') should be more than (P-Q).

This is confirmed by increase in the number of beats from 3 to 5 from case I to case II.

From the above confirmation, it can be concluded that our assumption of â€‹frequency of tuning fork P is greater than the frequency of tuning fork Q is correct.

So,

P - Q = 3 expression is valid.

**Frequency of tuning fork Q:**

Q = P - 3

= 432 - 3

=

**429 Hz**

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