The speed of a wave on a string is $150 \,ms^{-1}$ when the tension is $120 \,N$. The percentage increase in the tension in order to raise the wave speed by $20 \%$ is

As shown in the figure, a block of mass $9 \, kg$ is hung by a wire of area of cross-section $1 \, mm^2$ in a lift going up with an acceleration of $2 \, ms^{-2}$. If the speed of the transverse wave on the wire is $120 \, ms^{-1}$, the density of the material of the wire is (Acceleration due to gravity $= 10 \, ms^{-2}$)

$A$ block of mass $1\, kg$ is hanging vertically from a string of length $1\, m$ and mass per unit length $\mu = 0.001\, kg/m$. $A$ small pulse is generated at its lower end. The pulse reaches the top end in approximately .... $s$.

$A$ uniform rope of mass $0.1 \,kg$ and length $2.45 \,m$ hangs from a rigid support. The time taken by a transverse wave formed in the rope to travel through the full length of the rope is (Assume $g = 9.8 \,m/s^2$). (in $\,s$)

$A$ block $M$ hangs vertically at the bottom end of a uniform rope of constant mass per unit length. The top end of the rope is attached to a fixed rigid support at $O$. $A$ transverse wave pulse (Pulse $1$) of wavelength $\lambda_0$ is produced at point $O$ on the rope. The pulse takes time $T_{OA}$ to reach point $A$. If the wave pulse of wavelength $\lambda_0$ is produced at point $A$ (Pulse $2$) without disturbing the position of $M$,it takes time $T_{AO}$ to reach point $O$. Which of the following options is/are correct?

$A$ rope of length $L$ and mass $M$ hangs freely from the ceiling. If the time taken by a transverse wave to travel from the bottom to the top of the rope is $T$,then the time taken to cover the first half length is: