If a circular shaft is subjected to a torque T and a bending moment 'M' the ratio of the maximum shear stress to the maximum bending stress is given by :-A-2M/TB-T/2MC-2T/MD-M/2T-B-T/2M

B T/2M Maximum shear stress is 1.2N/mm2. Maximum longitudinal stress is 12N/mm2. The span to depth ratio is? Anybody, please help me.