Chapter 24.2, Problem 35SSC

To determine

To Explain: The motion of an armature in a motor.

Explanation of Solution

Introduction:

An electric motor is a device powered by DC current which converts electrical energy into mechanical energy. It’s made up of a current carrying coil place between magnets which rotates when current flows through the coil.

When the plane of armature of a motor is perpendicular to the magnetic field, the force exerted on the coil is zero. At this point there is no force exerted, but as per Newton’s first law of motion, the coil keeps on rotating because of rotational inertia, and after that the torque is applied again.

Conclusion:

The coil keeps on rotating because of rotational inertia.