4. When a circular bar tapering uniformly from diameter d1, at one end to diameter d2 at the other end, is subjected to an increase in temperature (t), then the thermal stress induced is (where ? = Coefficient of linear expansion, and E = Modulus of elasticity for the bar material)
5. A body is subjected to a tensile stress of 1200 MPa on one plane and another tensile stress of 600 MPa on a plane at right angles to the former. It is also subjected to a shear stress of 400 MPa on the same planes. The minimum normal stress will be
7. The shear force diagram fora cantilever beam of length l and carrying a gradually varying load from zero at free end and w per unit length at the fixed end is a
