Q4 (a) Describe two (2) applications that use the torsion principle in their operation. (2 marks) (b) (c) In order to obtain a simple theory in explaining the behaviour of shaft exerted with torque, there are few assumptions have been made. Explain what does it means by the maximum shearing stress in the shaft is within the elastic limit. (2 marks) A smooth thrust bearing at locations E and F support a 120 mm diameter shaft. At A, B, C, and D, the shaft was connected with gear. Torque is applied to the gears, as shown in Figure Q4(e). Using the figure details, determine: (i) the maximum shearing stress in each shaft segment. (10 marks) (ii) the maximum shearing stress in each shaft segment if the shaft is changed to a hollow type with a thickness of 5 mm and the outer diameter remains constant. (6 marks)