If a small concrete cube is submerged deep in still water in such a way that the pressure exerted on all faces of the cube is $$p,$$ then the maximum shear stress developed inside the cube is

The sketch shows a column with a pin at the base and rollers at the top. It is subjected to an axial force $$P$$ and a moment $$M$$ at mid-height. The reaction$$(s)$$ at $$R$$ is/are

A symmetric frame $$PQR$$ consists of two inclined members $$PQ$$ and $$QR$$, connected at $$‘Q’$$ with a rigid joint, and hinged at $$‘P’$$ and $$‘R’.$$ The horizontal length $$PR$$ is $$l.$$ If a weight $$W$$ is suspended at $$‘Q’,$$ the bending moment at $$‘Q’$$ is