Question

If the rotation is clockwise in this page, suppose, then in which direction will the thumb project if you curl your hand in the same direction of the rotation for bending moment diagram?

(a) It will point to the direction perpendicular to the plane of the paper and towards you

(b) It will point to the direction perpendicular to the plane of the paper and away from you

(c) It will point to the direction parallel to the plane of the paper and towards right

(d) It will point to the direction parallel to the plane of the paper and towards left

I had been asked this question during an interview.

I want to ask this question from Bending Moment Diagram in portion Internal Forces of Engineering Mechanics

Answer 1

The correct choice is (b) It will point to the direction perpendicular to the plane of the paper and away from you

To explain I would say: As the curling will give the direction perpendicular to the paper. But it does depend upon the rotation sense. In this example, the sense is clockwise. Thus the thumb goes into the paper. That is it goes away from the viewer. Thus the answer.