Two identical sonometer wires have a fundamental frequency of `500 Hz` when kept under the same tension . The percentage change in tension of one of the wires that would cause an occurrence of `5 beats//s` , when both wires vibrate together is

Options

A. 0.01
B. 0.02
C. 0.03
D. 0.04

Answer

B

Explanation

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 infty sqrt(T)` or `T infty n^(2)`
implies `(DeltaT)/(T) = 2(Deltan)/(n)`
implies percentage change in tension = 2(1%) = 2%