Question

Torsional moment is applied at the ___________ part of the beam.

(a) The centroid

(b) The left end

(c) The right end

(d) The axis beyond the body of the beam

I have been asked this question in final exam.

Question is taken from Internal Forces Developed in Structural Members topic in portion Internal Forces of Engineering Mechanics

Answer 1

The correct option is (a) The centroid

Easiest explanation: The torsional moment as said is made to be drawn at the centre of the beam. As it is generated by the various external forces, thus the centroid is the main point of the action of the various forces. Thus the forces which are made to be fallen on the body is having its effect over the centroid of the beam.