Steel ruptures when a shear stress of $3.5 \times 10^8 \, N \, m^{-2}$ is applied. The force needed to punch a $1 \, cm$ diameter hole in a steel sheet $0.3 \, cm$ thick is nearly:

Two wires of the same length and same material have radii $r_1$ and $r_2$. Their one end is fixed,and when an equal torque is applied to the other end,what is the ratio of their angular displacement?

$A$ square lead slab of side $50\, cm$ and thickness $10\, cm$ is subject to a shearing force (on its narrow face) of $9.0 \times 10^{4} \, N$. The lower edge is riveted to the floor. How much will the upper edge be displaced? (Given: Shear modulus of lead $G = 5.6 \times 10^{9} \, N/m^2$)

$A$ $2 \ m$ long rod of radius $1 \ cm$,which is fixed from one end,is given a twist of $0.8 \ radian$. The shear strain developed (in radian) will be $:-$

$A$ cube has side length $5$ cm and modulus of rigidity $10^5$ $N$/m$^2$. The displacement produced by a force of $10$ $N$ in the upper face of cube is . . . . . . mm.

Shear modulus is zero for