Wave Mechanics Vibration Of String Question 7
Question: Two similar sonometer wires given fundamental frequencies of 500Hz. These have same tensions. By what amount the tension be increased in one wire so that the two wires produce 5 beats/sec
[RPET 1999]
Options:
A) 1%
B) 2%
C) 3%
D) 4%
Show Answer
Answer:
Correct Answer: B
Solution:
To produce 5 beats/sec.
Frequency of one wire should be increase up to 505 $ Hz $ .
i.e.
increment of 1% in basic frequency.
$ n\propto \sqrt{T} $ or $ T\propto n^{2} $
Therefore $ \frac{\Delta T}{T}=2\frac{\Delta n}{n} $
Therefore percentage change in Tension = $ 2(1%)=2% $
BETA
