If the tension in a wire is made four times,then what will be the change in the speed of the wave propagating in it?

The extension in a string obeying Hooke's law is $x$. The speed of sound in the stretched string is $v$. If the extension in the string is increased to $1.5x$,the speed of sound will be (in $,v$)

$A$ 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 $\,s$)

$A$ string of length $1 \,m$ and mass $490 \,g$ is put under a tension of $25 \,N$. $A$ wave of frequency $120 \,Hz$ is sent along it. The speed of this wave is (in $\,m/s$)

$A$ uniform rope of length $12 \ m$ and mass $6 \ kg$ hangs vertically from a rigid support. $A$ block of mass $2 \ kg$ is attached to the free end of the rope. $A$ transverse pulse of wavelength $0.06 \ m$ is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is (in $m$)

Which of the following graphs is $CORRECT$?