Question

A bar is subjected to equal and opposite forces as shown in the figure. PQRS is a plane making angle $\theta$ with the cross-section of the bar. If the area of cross-section be ‘A’, then when is the shearing stress maximum

• A. $\theta =0^{\circ }$
• B. $\theta ={30}^{\circ }$
• C. $\theta ={45}^{\circ }$
• D. $\theta ={90}^{\circ }$

Answer 1

The correct option is C $\theta ={45}^{\circ }$

Shearing stress $=\frac{Fsin2\theta }{2A}$. It will be maximum when $sin2\theta =maxi.e.sin2\theta =1\Rightarrow 2\theta ={90}^{\circ }\Rightarrow \theta ={45}^{\circ }$.