A steel wire of length `1m`, mass `0.1kg` and uniform cross-sectional area `10^(-6)m^(2)` is rigidly fixed at both ends. The temperature of the wire is lowered by `20^(@)C`. If transverse waves are set up by plucking the string in the middle.Calculate the frequency of the fundamental mode of vibration.
Given for steel `Y = 2 xx 10^(11)N//m^(2)`
`alpha = 1.21 xx 10^(-5) per ^(@)C`

Options

A. `21Hz`
B. `42Hz`
C. `11Hz`
D. `22Hz`

Answer

C

Explanation

`n=(1)/(2L)sqrt(T//mu)=(1)/(2L)sqrt((YAalphaDeltatheta)/(mu))`