In a motor, the counter-emf voltage induced in the armature does what to the source current?

In an electric motor, the principle of counter-electromotive force (counter-emf) plays a crucial role in regulating the flow of current from the power source. When the motor operates, the armature winding generates a voltage known as counter-emf, which opposes the applied voltage from the power source. This opposition effectively reduces the net voltage that drives current through the circuit.

As the speed of the motor increases, the counter-emf rises, leading to a decrease in the amount of source current. This reduction occurs because the electrical power required to overcome the counter-emf is less than the total power supplied by the source. Therefore, it is accurate to say that counter-emf subtracts from the source voltage, which in turn reduces the current flowing from the power supply to the motor.

This interaction between the counter-emf and the source voltage is critical for the efficient functioning of electric motors and helps prevent excessive current draw from the supply, which could lead to motor damage or overheating.