Question

Which of the following is correct in the determination of the moment direction by curling of wrist?

(a) The thumb represents the direction of the force

(b) The thumb represents the direction of the moment

(c) The fingers represent the direction of the force

(d) The direction in which you curl your wrist is towards the direction of the distance from point of contact of force to the axis of rotation.

I have been asked this question in exam.

The query is from Moment of a Force topic in chapter Force System Resultants of Engineering Mechanics

Answer 1

Correct answer is (b) The thumb represents the direction of the moment

To elaborate: The curled hand represents a various thing. The direction of the moment axis is given by the thumb. The direction of the force is given by the fingers. As we place the fingers on the force and curl towards the rotational direction of the body about the axis.