Q2 A bending moment of 4 kN m is found to cause elastic failure of a solid circular shaft. An exactly simila shaft is now subjected to a torque 7. Determine the value of 7 which will cause failure of the shaft according to th following theories: (a) maximum principal stress; (b) maximum principal strain; (c) maximum shear strain energy. (v=0.3.) Which of these values would you expect to be the most reliable and why? Q1. A fixed quantity of helium gas of mass 0.6 kg undergoes a reversible process that has a linear path on the T-S diagram. The temperature and volume at the initial state are 38°C and 0.3 m³ respectively. The corresponding values are 260 °C and 0.73 m² at the final state. Calculate the heat transfer during the process. For helium assum that cv =3.12 kJ/kg K and R = 2.08 kJ/kgK.