Question

In the determination of the angle of the screw, the ratio kept in the inverse tangent function is the ratio of ________

(a) Vertical and Horizontal distance of the screw

(b) Horizontal and Vertical distance of the screw

(c) Vertical and Linear distance of the screw

(d) Linear and Horizontal distance of the screw

The question was posed to me in a job interview.

This intriguing question comes from Frictional Forces on Screws topic in chapter Friction of Engineering Mechanics

Answer 1

Right choice is (a) Vertical and Horizontal distance of the screw

Easy explanation: The angle of the threading in the screw is determined by inverse tangent trigonometric function. This is the generalised form of the function which is being used so as to get the value of the angle. In wedges, the same function is used so as to find the angle of a wedge. And in both, the case the ratio is vertical is to horizontal.