$A$ steel rod has a radius of $10 \,mm$ and a length of $1.0 \,m$. $A$ force stretches it along its length and produces a strain of $0.32 \%$. The Young's modulus of the steel is $2.0 \times 10^{11} \,N/m^2$. What is the magnitude of the force stretching the rod in $kN$?

$A$ one metre steel wire of negligible mass and area of cross-section $0.01 \,cm^2$ is kept on a smooth horizontal table with one end fixed. $A$ ball of mass $1 \,kg$ is attached to the other end. The ball and the wire are rotating with an angular velocity of $\omega$. If the elongation of the wire is $2 \,mm$, then $\omega$ is (Young's modulus of steel $= 2 \times 10^{11} \,N/m^2$)

An Indian rubber cord $L$ metre long and area of cross-section $A$ $m^2$ is suspended vertically. The density of rubber is $D$ $kg/m^3$ and Young's modulus of rubber is $E$ $N/m^2$. If the wire extends by $l$ metre under its own weight,then the extension $l$ is:

Two wires of the same length and radius are joined end-to-end and loaded. The Young's moduli of the materials of the two wires are $Y_{1}$ and $Y_{2}$. If the combination behaves as a single wire,then its equivalent Young's modulus is:

Two wires of copper having the lengths in the ratio $4:1$ and their radii in the ratio $1:4$ are stretched by the same force. The ratio of longitudinal strain in the two will be

What is the Young's modulus and bulk modulus for a perfect rigid body?