A steel rod $100\, cm$ long is damped at into middle. The fundamental frequency of longitudinal vibrations of the rod are given to be $2.53\, kHz$. What is the speed of sound in sound is steel ? (in $km/s$)

A metallic wire of length $L$ is fixed between two rigid supports. If the wire is cooled through a temperature difference $\Delta T$ ($Y$ = young’s modulus, $\rho$ = density, $\alpha$ = coefficient of linear expansion) then the frequency of transverse vibration is proportional to : 

A wave travelling along positive $x-$ axis is given by $y = A\sin (\omega \,t - kx)$. If it is reflected from rigid boundary such that $80\%$ amplitude is reflected, then equation of reflected wave is

If $n _{1}, n_{2}$ and $n _{3}$ are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency $n$ of the string is given by

A string is stretched between two fixed points separated by $75\,cm$ . It is observed to have resonant frequencies of $420\,Hz$ and $315\,Hz$ . There are no other resonant frequencies between these two. Then, the lowest resonant frequency for this string is  ..... $Hz$

The transverse displacement of a string clamped at its both ends is given by 

$y\left( {x,t} \right) = 2\,\sin \,\left( {\frac{{2\pi }}{3}x} \right)\,\cos \,\left( {100\,\pi t} \right)$ 

where $x$ and $y$ are in $cm$ and $t$ is in $s$. Which of the following statements is correct ?