Which one of the following expresses the height of rise or fall of a liquid in a capillary tube ?(w = Specific weight of the liquid α = Angle of contact of the liquid surface σ = Surface tension)

Two closely-coiled springs A and B of the same material, same wire and same number of turns are subjected to an axial load of W. The mean diameter of spring A is half that of spring B. The ratio of deflection of spring B to that of spring A will be

A column ABCD (2y_{1} x 2y_{2}) of rectangular section carries a load P at Z having the co-ordinates (x, y) as shown in the given figure. If the compressive streses are taken as positive and area A = 2y_{1} x 2y_{2} = 4y_{1}y_{2} and the moment of inertia about x and y axis being I_{xx} and I_{yy} respectively, then the stress at the corner D is