Circle the correct answer true or false T F Maximum shear st

Circle the correct answer, true or false? T F Maximum shear stress is in the middle of the shaft cross-section T F Materials are subjected to plastic deformation before they can deform elastically T F Elastic stress is uniformly distributed over the cross-section of an axially loaded member T F Surface scratches cause stress concentrations in rotating shafts T F Shafts with triangular cross-section are most efficient for transporting torque T F Plastically deformed materials unload elastically T F Cracks in large concrete slabs are caused by temperature fluctuations T F Shafts rotating at higher frequencies transmit more power T F Moments sign notation is determined by the left hand rule T F Shear modulus can experimentally determine using the torque formula

Solution

1) False - Maximum shear stress will not occur at the centre of cross section it will occur at outer surface of cross section.

2) False :- Materials generally first deform elastically after that they will deform plastically.

3) True :- Yes elastic stresses are uniformly distributed over the cross section

4) True :- Surface scratches will cause stress concentrations which will reduce the strength of the material

5) False

6)False :- No plastically deformed material unload plastically.

7)True :- Temperature fluctuation will cause cracks.

8) True :- shaft rotating at higher frequencies transmits more power because power is directily proportional to frequency.

9) False :- Moment sign notation is determine by right hand rule.

10) True :- shear modulus can be experimentally determined by torque formula.