Question

Explain the construction and working principle of an electric motor.

Answer 1

Electric Motor:

An electric motor turns electrical energy into mechanical energy.

The diagram of an electric motor is given below:

Components of Electric Motor:

1. Power Supply: Usually direct current (DC) source is used to power the electric motor. Its primary function is to supply power to the armature.
2. Field Magnet: Field Magnet can be a permanent magnet or an electromagnet. The magnetic field, as a result of Fleming's left-hand law, aids in the generation of torque on the rotating armature coil.
3. Armature/Rotor: It is used to enhance current flow across the field, which creates a torque on the rotating machine. It is also used to generate emf.
4. Commutator: A commutator is used to reverse the direction of the electric field.
5. Armature Coil: It is the coil through which the current flows in an armature.
6. Brushes: Brushes aid in transferring current between fixed wires and moving components, most notably rotating shafts.
7. Axle: The axle aids in creating contact between the rotor and the electromagnet.

Working Principle of Electric Motor:

1. An electric motor operates on the idea that when a rectangular current-carrying coil is put in a magnetic field, a force acts on the coil, causing it to rotate continuously.
2. According to Fleming's left-hand rule, if we make our thumb, forefinger, and middle finger mutually perpendicular to each other, then the forefinger gives the direction of the magnetic field, the middle finger gives the direction of the current and the thumb gives the direction of the thrust or motion.
3. For instance, make a little distance between the poles of two bar magnets that are facing each other.
4. A loop is made with a small conductive wire. Maintain this connection between the magnets so that it remains within the magnet's field of influence.
5. Now comes the final section. Connect the loop ends to the battery connections. As electricity passes across your simple circuit, one will notice that your loop moves.
6. The magnetic field produced by the magnet interferes with the electrical current flow generated by the conductor.
7. Because the loop has turned into a magnet, it will attract one side to the magnet's north pole and the other to the magnet's south pole.
8. This causes the loop to rotate indefinitely.