wave_mechanics Beats Question 46

Question: The frequency of tuning forks A and B are respectively 3% more and 2% less than the frequency of tuning fork C. When A and B are simultaneously excited, 5 beats per second are produced. Then the frequency of the tuning fork ‘A’ (in Hz) is

[EAMCET 2001]

Options:

A) 98

B) 100

C) 103

D) 105

Show Answer

Answer:

Correct Answer: C

Solution:

Let n be the frequency of fork C then $ n _{A}=n+\frac{3n}{100}=\frac{103n}{100} $ and $ n _{B}=n-\frac{2n}{100}=\frac{98}{100} $ but $ n _{A}-n _{B}=5 $

Therefore $ \frac{5n}{100}=5 $

Therefore $ n=100Hz $ \ $ n _{A}=\frac{(103)(100)}{100}=103Hz $