$A$ $2 \ m$ 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.

$A$ rectangular block of size $10\,cm \times 8\,cm \times 5\,cm$ is kept in three different positions $P, Q,$ and $R$ in turn as shown in the figure. In each case,the shaded area is rigidly fixed and a definite force $F$ is applied tangentially to the opposite face to deform the block. The displacement of the upper face will be

$A$ wire of length $1 \text{ m}$ and radius $2 \text{ mm}$ is vertically clamped. The lower end is twisted through an angle of $45^{\circ}$. The angle of shear is $.....$ (in $^{\circ}$)

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:

Shear modulus is zero for