Question

Explain the principle of electric generators and the function of brushes.

Answer 1

Hint: In order to solve this question we need to understand Faraday’s first law of electromagnetic induction. An Electric generator is a device which converts mechanical energy into electrical energy, we will discuss its working and the principle on which it works.

Complete answer:
Electric generator is a device which converts mechanical energy into electrical energy.
It works on the principle of Faraday’s law of electromagnetic induction which states that whenever there is change in magnetic flux through a loop over the time then emf would be induced in it which in turn induces electric current inside the loop.

Now the magnetic flux is defined as the dot product of the magnetic field and cross sectional area under the magnetic field so it can be changed in three different ways. First is by changing magnetic field, second is by changing area under constant magnetic field and third is by changing orientation.

Working: Electric generator is made of coil containing wounding of copper jointly known as armature, a horseshoe magnet or cylindrical shape magnet, split rings, brushes, a galvanometer and wires closing loop.Now the armature is connected to a motor which is rotated by using mechanical energy of diesel, petrol etc.

Now when the loop rotates in magnetic field then due to continuous changing in magnetic flux emf induced in loop which in turn induces electric current.Now the split rings attached changes the direction of rotation of loop after few minutes so as to maintain change in magnetic flux or emf across loop Brushes used as connection between loop and wires so that current generated in loop could be passed to external circuit containing galvanometer

Note: It should be remembered that the generator works exactly opposite of the electric motor which converts electrical energy into mechanical energy. Both are of great use and used in specific places. Also electric generators produces current of Alternating current in nature.