# > Why Change Of Magnetic Flux Induces Current In It?

1. May 26, 2014

### Ankit

Why change of magnetic flux with the time through a coil induces current in it?
Please tell me that what happen to charge in the coil if the magnet or electromagnet wave around this? Also, why a constant magnetic flux does not induces current?

2. May 26, 2014

### Staff: Mentor

This is a pretty involved question that doesn't have a simple answer. What do you know about it currently? What's your level of education in the subject?

3. May 27, 2014

### Ankit

I am the beginner in magnetism but intermediate in electricity.

4. May 29, 2014

### siddharth5129

As far as classical electrodynamics goes ( I don't know if more advanced theories of physics shed more light on this question ) this is one of maxwell's four fundamental postulates ( or equations ) of electrodynamics. So within the framework of the classical theory, this is simply how it works. It's a fundamental law and is just so. Electric and magnetic fields are just linked in this fundamental way. Incidentally, a time varying electric flux through a coil will also induce a circumferential magnetic field and this law displays a compelling symmetry with the other one.
It's kind of like asking why there exists a force of attraction between two opposite charges. You took that for granted didn't you ?

5. May 29, 2014

### WannabeNewton

It's a consequence of special relativity (SR) so, contrary to siddharth5129's statements, classical physics can perfectly well explain its origin. However if you don't know SR then I'm not sure how effectively one could explain it to you. In any event I would recommend taking a look at chapter 3 of Schwartz "Principles of Electrodynamics".

6. May 29, 2014

### siddharth5129

oh. I'm sorry. My bad then.