Question

Explain what is the significance of Polar moment of Inertia (J)

Answer 1

Polar moment of inertia(J) is a measure of a body's ability to resist torsional deformation torque is applied to it on a specified axis.In simple terms, polar moment of inertia is the resistance offered by a beam or shaft when it is being distorted by torsion.This opposition arises from the cross-sectional area and does not depend on the material composition.

If the polar moment of inertia is of higher magnitude then the torsional resistance of the object will also be greater i.e, More torque will be required to turn the shaft at an angle as compared to less torque.