# The factors in this system that would generate CEMF

1. May 6, 2013

### Wiz700

Hi

I have a Solenoid(No core) and a small magnet that is stationary in it.
The Solenoid is powered off/on. What would cause Counter-EMF if the Solenoid is on/off?
Only the motion of the magnet?

What are other factors would generated EMF in my coil?
Other than the magnet's motion + the power input of course :P

2. May 6, 2013

### CWatters

The inductance of the coil perhaps.

3. May 7, 2013

Do explain!

4. May 7, 2013

### Wiz700

Another thing, the motion of the magnet is a result of the attraction or repulsion of the two.
Only AFTER the force is applied the motion starts. So CEMF is a result of the reaction, well on of the results motion is too a result :)

In fact! Motion is a result of the magnet + electromagnet's attraction/repulsion and CEMF is a result of that motion.

5. May 7, 2013

### CWatters

When turned on the current through the coil inductance can't change instantly. The coil voltage will initially be higher. As the current builds the voltage will fall to it's final value. During that (brief?) time the voltage is higher than normal. Can that be distinguished from CEMF?

6. May 8, 2013

### Wiz700

Well I just learned "Inductance" as: The opposing EMF that is generated by changing current, thus caused a change in the magnetic field = change in the magnetic flux thus INDUCED EMF opposes the applied EMF.

I assume this is what you meant? "L"?