Wave Mechanics Vibration Of String Question 35

Question: Two perfectly identical wires are in unison. When the tension in one wire is increased by 1%, then on sounding them together 3 beats are heard in 2 sec. The initial frequency of each wire is :

[Pb. PET 2002]

Options:

A) $ 220{{s}^{-1}} $

B) $ 320{{s}^{-1}} $

C) $ 150{{s}^{-1}} $

D) $ 300{{s}^{-1}} $

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Answer:

Correct Answer: D

Solution:

Similar to Q.

30 Initial frequency of each wire (n) $ =\frac{\text{(Number}\ of\ beats\ heared\ per\ \text{sec)}\times 200}{\text{(per}\ centage\ change\ in\ tension\ of\ the\ \text{wire)}} $

$ =\frac{(3/2)\times 200}{1}=300{{\sec }^{-1}} $