Introduction to electromagnetic induction
We have heard about the production of electricity in the magnetic space.
If we bring any conductor in the magnetic field then we have observed that some current flows through the conductor.
We can take an example of a bulb which was placed close to a magnet.
We will notice that bulb can glow just because of magnetism but we are not aware of the reasoning behind the lightening of bulb.
The reason behind the flow of electricity in the bulb due to a magnet can be explained by the concept of electromagnetic induction.
Let's understand the electromagnetic induction.
Suppose we have placed a conductor in a magnetic field,
Let us suppose the current,
is flowing in the downward direction.
A force will be induced due to the flow of current in the magnetic field. The direction of the force can be evaluated by Fleming's left-hand rule.
If we apply Fleming's left-hand rule then the direction of force will be towards us.
Now let's change the situation, suppose a conductor is placed in the magnetic field and we are applying force on it.
We need to understand whether the current will flow when we will apply the force on the conductor that is placed in a magnetic field.
We can consider a situation in which we are varying the magnetic field whereas the conductor remains stationary.
In another case, we are moving the conductor and keeping the magnetic field constant. We need to understand the flow of current.
These were some common practical problems about the flow of current which were experimented by the scientists in
In 1831, Michael Faraday experienced the same questions and he came up with a theory to give answers to these questions.
Faraday first kept the magnetic field constant and did not move the conductor. He did not find any current generation.
In another case, he moved the conductor and again kept magnetic field constant.
This time he experienced some current flowing through the conductor.
This situation is similar as we have two bulbs in a circuit without a battery.
We bring a magnet,
close to this circuit and move the magnet then we experience that bulbs start glowing.
Here, we can say that whenever a conductor is placed in a varying magnetic field then a current starts to flow through the conductor.
Let's do a home exercise to experience current in a conductor due to magnet.
Let's take a foil role and wind a coil over the role.
Now, we will connect a galvanometer to this circuit and check the needle of the galvanometer.
Now bring a magnet closer to this circuit and move the magnet inside the coil.
After some time, we will experience that the needle of the galvanometer is deflected.
The deflection in the needle of the galvanometer shows that the current is flowing through the coil. This process of flowing of current due to the magnet is electromagnetic induction.
This is how we can understand the concept of electromagnetic induction and can easily practice the concept at our home.
When we place a conductor in a magnetic field in which the current is flowing.
Then we can experience a force in the conductor and the direction of the force can be determined by Fleming's left-hand rule.
If we place a conductor in the changing magnetic field, then we observe a current flowing through the conductor.
We can experiment with the current flow by taking a coil wrapped on a role and moving a magnet around coil.