# Electromagnetic induction

• Karan Punjabi
In summary, the discussion focused on understanding the concepts of Lenz's law and Faraday's law. It was explained that the current is not trying to keep the flux constant, but rather the charges respond to changes in flux. This means that the current is only present when there is a changing magnetic flux linkage, and it will stop once the change stops. The reason for this is due to the relationship between electrical and magnetic fields and the invariance of the speed of light. The discussion also touched on the difference between induced emfs and currents, with the former being a consequence of changing flux while the latter requires a continuous change in flux to sustain it.

#### Karan Punjabi

Guys, I have read Lenz's law and Faraday's law. My question is when the current is overall trying to keep the magnetic flux constant as that in initial time then if I permanently change the flux then why the current is not flowing through the conductor continuously to keep initial flux constant. Thankyou

The current is not trying to keep the flux constant - the charges respond to changes in flux.

Simon Bridge said:
The current is not trying to keep the flux constant - the charges respond to changes in flux.
Can you elaborate please. Because I want real concept. I want to understand it.

Simon Bridge said:
the charges respond to changes in flux.

In other words current produced by changing the flux in a coil is proportional to the time rate of change of the flux in that coil. Once the change stops the current stops, end of story. In order to sustain the current you must continuously change the flux.

Faradays and Lenz's laws concern induced emfs...not currents.
There is a very subtle but important distinction.
You will always get an induced emf in a conductor when there is a changing magnetic flux linkage. This does not mean that you will always get a current.

Ohk...I read an article and there I concluded that there must be a relative motion between conductor and magnetic field to generate EMF. Why it is like that?

Its a consequence of electrical and magnetic fields being manifestations of the same fundamental force and the invariance of the speed of light. Bottom line: it happens because that is how the Universe works.

What was the article? Where?

## 1. What is electromagnetic induction?

Electromagnetic induction is the process by which a changing magnetic field induces an electric current in a conductor.

## 2. Who discovered electromagnetic induction?

Electromagnetic induction was discovered by Michael Faraday in 1831.

## 3. How does electromagnetic induction work?

Electromagnetic induction works by creating a changing magnetic field near a conductor. This changing magnetic field then induces an electric current in the conductor.

## 4. What are some practical applications of electromagnetic induction?

Some practical applications of electromagnetic induction include generators, transformers, and induction cooktops.

## 5. What is the difference between electromagnetic induction and electromagnetic radiation?

Electromagnetic induction involves the transfer of energy through a changing magnetic field, while electromagnetic radiation involves the transfer of energy through oscillating electric and magnetic fields. Additionally, electromagnetic induction only occurs in conductors, while electromagnetic radiation can occur in both conductors and non-conductors.