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?

(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 have been asked this question during an interview.

I'm obligated to ask this question of Moment of a Force topic in portion Force System Resultants of Engineering Mechanics

Answer 1

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

The explanation is: 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.