8) The warping function 0(x,y) for a cross section under torque is: a) zero for all cross sections with double symmetry; b) non-zero for all cross sections except for circular; c) a function satisfying Poisson's differential equation. 9) The nucleus of inertia of a cross section is a region in the plane of the section which can be determined: a) by imposing the centre of pressure of a generic axial force to coincide with each vertex of the section; b) by imposing the centre of pressure of a generic axial force to lie at 1/3 the dimensions of the section; c) by imposing the neutral axis to overlap each side of the section. 10) Given the following frame system, the Euler's critical load for the structure is (plot the deflected structure on the booklet): a) P - REJ = h/2 EA-00 EJ-00 B41 π² EJ EJ with lo=2h; b) P = with o=h; c) P = with l=0.7h. cr cr

8) The warping function 0(x,y) for a cross section under torque is: a) zero for all cross sections with double symmetry; b) non-zero for all cross sections except for circular; c) a function satisfying Poisson's differential equation. 9) The nucleus of inertia of a cross section is a region in the plane of the section which can be determined: a) by imposing the centre of pressure of a generic axial force to coincide with each vertex of the section; b) by imposing the centre of pressure of a generic axial force to lie at 1/3 the dimensions of the section; c) by imposing the neutral axis to overlap each side of the section. 10) Given the following frame system, the Euler's critical load for the structure is (plot the deflected structure on the booklet): a) P - REJ = h/2 EA-00 EJ-00 B41 π² EJ EJ with lo=2h; b) P = with o=h; c) P = with l=0.7h. cr cr