Two instruments having stretched strings are being played in unison . When the tension in one of the instruments is increases by ` 1% , 3` beats are produced in ` 2 s`. The initial frequency of vibration of each wire is

Options

A. 600Hz
B. 300Hz
C. 200Hz
D. 150Hz

Answer

B

Explanation

`v propsqrt(T), v'propsqrt(T+(1)/(100)T)`
`(v')/(v)=(1+(1)/(100))^(1//2)=1+(1)/(200)`
`(v'-v)/(v)=(1)/(200) or (3)/(2v)=(1)/(200) or v=300Hz`.