Inductance
As we have discussed, coils act to oppose changes in magnetic flux. A coil's inductance is a measure of the coil's resistance to a change
in magnetic flux.
An easy way to obtain a magnetic flux in a coil is to set up a current in the coil.
If the current is constant the flux is constant; if the current changes the flux changes.
In this situation Faraday's Law can be written in terms of the rate of change of current instead of the rate of change of flux, since the flux changes only because the current changes:
| e |
= |
– N |
| DFB
|  |
| Dt
|
|
= |
– L |
| DI
| |
| Dt
|
|
where L is known as the self-inductance of the coil. The unit for inductance is the henry (H).
Resistance is a measure of a conductor's resistance to the flow of charge.
Self-inductance is a measure of a coil's resistance to a change
in this flow.