To increase torsional resistance, what should be done to the polar moment of inertia "J"?

To increase torsional resistance in structural elements, the polar moment of inertia, represented as "J," must be increased. The polar moment of inertia is a geometric property that measures an object's ability to resist torsional or twisting forces. It is directly related to the distribution of the material around the axis of torsion.

Increasing "J" can be achieved by either changing the shape or size of the cross-section of the structural member. For instance, using a thicker section or a more strategically shaped profile (like an I-beam or a hollow tube) can effectively distribute the material further from the center of rotation, which enhances the member's ability to resist twisting forces.

When "J" is larger, it means that the material is better positioned to resist the changes in angles that occur under torsional loads, thereby increasing the overall torsional strength of the structure. Ensuring that "J" is sufficiently large is crucial in designing elements that will be subjected to significant torsional moments, such as beams in bridges or shafts in mechanical applications.

The other choices, which suggest decreasing, maintaining, or merely inspecting "J," do not contribute to increasing torsional resistance and may compromise the structural integrity of an element under torsional loads. Therefore,