Question

State two ways by which the speed of rotation of an electric motor can be increased.

Answer 1

Hint: The electric motor has some parameters to control the speed. By adjusting the parameters, the speed of the rotation of the electric motor is changed. Some parameters are directly proportional to the speed and some parameters are inversely proportional to the speed.

Complete step by step answer:
The speed of the rotation of the electric motor is increased by changing the current, by increasing the strength of the current which is supplied to the electric motor, then the speed of the rotation of the electric motor can be increased. And also, the number of the turns of the coil is increased in the rotor of the electric motor, the speed of the rotation of the electric motor can be increased. And then by decreasing the magnetic flux of the electric motor, then the speed of the motor can be increased. The magnetic flux can be changed by changing the current supplied to the electric motor.

The speed of the rotation of the electric motor can be increased by changing the resistance of the circuit, by decreasing the resistance of the electric motor, there is the increase of the current then the current strength will increase. So, the speed of the rotation of the electric motor will increase. The voltage supplied to the electric motor is changed, then the speed of the electric motor will be changed. Electric motors rotate at different speeds with different voltages.

Note: For electric motors some parameters are directly proportional, the terms which are directly proportional to the speed, and the parameters are increased, the speed is increased. The terms which are inversely proportional to the speed, and the parameters are decreased, the speed is increased.