Question

Which of the following is true for bending moment diagram?

(a) Total moment of various forces acting on the body is the vector sum of all moments

(b) Total moment of various forces acting on the body is the algebraic sum of all moments

(c) Total moment of various forces acting on the body is always zero

(d) Total moment of various forces acting on the body is the vector sum of all moments which is perpendicular to each other forces

I have been asked this question in quiz.

My question is based upon Bending Moment Diagram in section Internal Forces of Engineering Mechanics

Answer 1

Correct answer is (a) Total moment of various forces acting on the body is the vector sum of all moments

To elaborate: The moment is the vector quantity. Thus the value of the total moment caused by various forces acting on the body is the vector sum of all the vectors. Also, the moments are not perpendicular to each other, unless it is specified. Thus assumptions cant be taken for the direction of the moment.