Question

A shaft with a circular cross-section is subjected to pure twisting moment. The ratio of the maximum shear stress to the largest principal stress is

• A. 2.0
• B. 1.0
• C. 0.5
• D. 0

Answer 1

The correct option is B 1.0

For the case of pure shear
${\sigma }_1={\tau }_{\text{max}}$
${\sigma }_2=-{\tau }_{\text{max}}$
Required ratio $=\frac{{\tau }_{\text{max}}}{{\sigma }_1}=\frac{{\sigma }_1}{{\sigma }_1}=1$