Question

The work done in rotating a body from angle ${\theta }_1$ to angle ${\theta }_2$ by a constant torque $\tau$ will be :

• A. $\frac{\tau }{({\theta }_1-{\theta }_2)}$
• B. $\tau ({\theta }_2-{\theta }_1)$
• C. $0$
• D. $\frac{({\theta }_1-{\theta }_2)}{\tau }$

Answer 1

Answer: (B)

$\tau ({\theta }_2-{\theta }_1)$

Work done in angular displacement is given as ${\int }_{{\theta }_1}^{{\theta }_2}dW={\int }_{{\theta }_1}^{{\theta }_2}\tau d\theta$. For constant terms we get the relation as $W=\tau \left({\theta }_2-{\theta }_1\right)$