The maximum torsional stresses will be created:Question 3Select one:a.On the external surface of the shaftb.In the centroid of cross-sectionc.At the supports

Step 1: Break Down the Problem

To determine where the maximum torsional stresses occur in a shaft, we need to analyze the behavior of the material under torsion.

Step 2: Relevant Concepts

1. Torsional Stress Formula: The torsional stress ($\tau$) in a circular shaft can be calculated using the formula: $\tau = \frac{T \cdot r}{J}$ where:

   • $T$ = applied torque
   • $r$ = radius of the shaft
   • $J$ = polar moment of inertia

2. Stress Distribution: Torsional stresses are not uniform and often reach their maximum value at specific locations in the shaft.

Step 3: Analysis and Detail

• External Surface of the Shaft: The formula indicates that stress increases linearly from the center to the outer surface. Therefore, it can be inferred that the maximum stress occurs on the external surface where the radius is largest.

• Centroid of Cross-section: The centroid of the cross-section does not correlate to maximum stress since this point experiences the least amount of torsional stress.

• At the Supports: At this location, while there may be additional reactions or constraints, it is not where torsional stresses are maximized when torque is applied.

Step 4: Verify and Summarize

Based on the analysis, maximum torsional stresses will occur at the following location: On the external surface of the shaft.

Final Answer

The maximum torsional stresses will be created: a. On the external surface of the shaft.