question_answer

A solid shaft of diameter 100 mm, length 1000 mm is subjected to a twisting moment 'T'. The maximum shear stress developed in the shaft is 60 N/mm. A hole of 50 mm diameter is now drilled throughout the length of shaft. To develop a maximum shear stress of 60 N/ mm in the hollow shaft, the torque 'T' must he reduced by

A) T/4                              

B) T/8

C) T/12                             

D) T/16