Electromagnetic Induction

Electromagnetic Induction

Fig:- [As you can see, a non current carrying wire is hold down on the magnetic field that is created by placing two magnets of opposite poles a little close apart.]

Magnetic Flux Linkage

The intersecting point between magnetic flux and wire is known as magnetic flux linkage.

*[This intersection is shown in the above picture as a red dot between the flux line and wire.]

Flux Linkage Cut

If you move the wire or any of the magnets, the magnetic flux linkage alters. This is known as flux linkage cut.

*[Like if you try to move the wire from its stationary position to up or down, or either side, or if you move the magnets anyway, then the contact breaks and this is known as Flux Linkage Cut.]

Electromagnetic Induction

E.m.f.:- Electromotive force/Voltage

When there is a magnetic flux linkage cut in the wire, there is an induced e.m.f. (voltage) produced in the wire. This phenomenon is known as electromagnetic induction. The ways of increasing e.m.f. in a wire:-

1. Moving the wire more quickly.
2. By using a stronger magnet.
3. Wrapping the wire into a coil.

*[This voltage is powerful and strong]

Induced E.m.f. and coil

Fig:- *[I’m sorry because there isn’t enough light appearing in the image above but those who have book, pls have a look at page 190, and those who don’t have book, pls struggle, remember, no pain, no gain.]

When we move the magnet backward and forward inside the coil, the voltmeter gives us a reading due to electromagnetic induction (as a current is produced). Ways of increasing the induced e.m.f.:-

1. Using stronger magnet.
2. Moving the magnet faster
3. Using coil with more turn.
4. Using coil with larger cross-sectional area.

Faraday’s law of electromagnetic induction.

 The size of induced emf (voltage)across the end of a wire (coil) is directly proportional to the rate at which the magnetic lines of flux are being cut.

*[There’s something like Lenz’s law, you’ll get better and clear understanding if you ask it to your teacher]