Question

An electric motor rotates a wheel at a constant angular velocity $\omega$ while opposing torque is $\tau$. The power of that electric motor is :

• A. $\frac{\tau \omega }{2}$
• B. $\tau \omega$
• C. $2\tau \omega$
• D. $\frac{\tau }{\omega }$

Answer 1

The correct option is B $\tau \omega$

Power of Motor $\overrightarrow{P}=\overrightarrow{\tau }\times \overrightarrow{\omega }$
The motor is rotating at a constant angular velocity $\omega$ against a Torque $\tau$.
$\therefore P=\tau \times \omega =\tau \omega$