What is the modulus of rigidity of a liquid?

The edge of an aluminium cube is $10\; cm$ long. One face of the cube is firmly fixed to a vertical wall. $A$ mass of $100\; kg$ is then attached to the opposite face of the cube. The shear modulus of aluminium is $25\; GPa$. What is the vertical deflection of this face?

Two wires $A$ and $B$ of the same length and of the same material have the respective radii $r_1$ and $r_2$. Their one end is fixed to a rigid support,and at the other end,an equal twisting couple is applied. The ratio of the angle of twist at the end of $A$ to the angle of twist at the end of $B$ will be:

The units of modulus of rigidity are

The ratio of lengths of two rods $A$ and $B$ of the same material is $1:2$ and the ratio of their radii is $2:1$. What is the ratio of the modulus of rigidity of $A$ and $B$ (in $:1$)?

The strain energy stored in a body of volume $V$ due to shear strain $\phi$ is (shear modulus is $\eta$ ).