Question

Radius of gyration is indirectly to the parallel axis theorem. The parallel axis theorem gives the moment of inertia ______________ to the surface of considesrance.

(a) Linear

(b) Non-Linear

(c) Perpendicular

(d) Parallel

This question was addressed to me in an international level competition.

Question is from Radius of Gyration of an Area in chapter Moments of Inertia of Engineering Mechanics

Answer 1

Correct choice is (c) Perpendicular

The explanation: Parallel axis for any area is used to add the two mutually perpendicular moment of inertias for areas. It gives a moment of inertia perpendicular to the surface of the body. That is the moment of inertia perpendicular to the surface in considerance.