Two identical wires of length `l and 2l` vibrate with
fundamental frequencies 100 Hz and 150 Hz
respectively. What is the ration of their tensions?

Options

A. 9
B. 11
C. 8
D. 6

Answer

a

Explanation

Let ` mu_(1)=mu_(2)=mu`
`rArr v_(1)=100 = 1/(2L) sqrt(T_(1)/mu)`
`rArrv_(2)=150=1/(2(2L))sqrt(T_(2)/mu)`
`v_(1)/v_(2)=100/150=2sqrt(T_(1)/T_(2))`
or `T_(1)/T_(2)=(10/30)^(2)=1/9`
or `T_(2)=9T_(1)`