Question

Is emf induced in DC motor?

Answer 1

Yes, electromotive force (EMF) is induced in a DC motor.

When a DC motor operates, it converts electrical energy into mechanical energy. The key to understanding induced EMF in a DC motor is to look at how the motor works. Inside the motor, there is a rotating coil (the armature) placed in a magnetic field. As the armature rotates, the magnetic field induces a voltage in the coil according to Faraday's Law of Induction.

This induced EMF, also known as back EMF (or counter EMF), opposes the applied voltage from the power source. The faster the motor spins, the greater the back EMF becomes, which reduces the current flowing through the armature. This back EMF plays an important role in controlling the motor’s speed.

At startup, when the motor is not yet spinning, there is little back EMF, so the current is high, and the motor accelerates. As the motor reaches its operating speed, the back EMF increases, limiting the current and stabilizing the motor's speed.

So, in summary, yes, EMF is induced in a DC motor, and this induced back EMF is a key factor in how the motor functions.