Question

A wire having a linear mass density `5.0xx10^(3) kg//m` is stretched between two rigid supports with tension of 450 N. The wire resonates at a frequency of `420 Hz`. The next higher frequency at which the same wire resonates is` 480 N`. The length of the wire is
A. `2.0 m`
B. `2.1 m`
C. `2.5 m`
D. `3 m`

Answer 1

Correct Answer - B
Two consecutive frequencies are 420 Hz and 480 Hz. So the fundamental frequency will be `60 Hz`.
`60=(1)/(2xxl)sqrt((450)/(5xx10^-3))impliesl=2.1m`
Hence (b).