Wave Mechanics Vibration Of String Question 7
Two similar sonometer wires have fundamental frequencies of 500Hz. These have the same tensions. By what amount should the tension be increased in one wire so that the two wires produce 5 beats/sec
[RPET 1999]
Options:
1%
2%
3%
4%
Show Answer
Answer:
Correct Answer: B
Solution:
To produce 5 beats per second.
Frequency of one wire should be increased 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, the percentage change in Tension = $ 2(1%) = 2% $
BETA
