The value of Young's modulus for a perfectly rigid body is ...........

Overall changes in volume and radii of a uniform cylindrical steel wire are $0.2 \%$ and $0.002 \%$ respectively when subjected to some suitable force. Calculate the longitudinal tensile stress acting on the wire. (Given: Young's modulus $Y = 2.0 \times 10^{11} \ N/m^2$)

Which of the following graphs correctly depicts the spring constant $k$ versus the length $l$ of the spring?

$A$ load of $2 \,kg$ produces an extension of $1 \,mm$ in a wire of $3 \,m$ in length and $1 \,mm$ in diameter. The Young's modulus of the wire will be .......... $Nm^{-2}$.

$A$ steel wire $1.5\,m$ long and of radius $1\,mm$ is attached with a load of $3\,kg$ at one end,while the other end is fixed. It is whirled in a vertical circle with a frequency of $2\,Hz$. Find the elongation of the wire when the weight is at the lowest position. (Given: $Y = 2 \times 10^{11}\,N/m^2$ and $g = 10\,m/s^2$)

If Young's modulus for a material is zero,then the state of material should be