Question

A circular shaft of diameter D is subjected to a torque T. The maximum shear stress of the shaft will be

• A. proportional to $D^3$
• B. proportional to $D^4$
• C. inversely proportional to $D^3$
• D. inversely proportional to $D^4$

Answer 1

The correct option is C inversely proportional to $D^3$

${\tau }_{max}=\frac{T}{Z_P}$
$=\frac{T\times 16}{\pi D^3}$
$\Rightarrow {\tau }_{max}\alpha \frac{1}{D^3}$