Magnet Myths and Misconceptions

[verpies]

2-And do you agree that when the power to the inductor is abruptly disconnected,the magnetic field gives back the power it took to create it?-the rest of the power of course was dissipated as heat.

Yes, but you have to be more precise when you write "give back".  For example, the energy stored in an inductor's magnetic field can be discharged into a capacitor.  Also, it is not necessary for an inductor to be abruptly disconnected from a power supply, for this to happen, because current can circulate in an inductor without the power supply being connected at all (as in a shorted coil).

During the time while the energy is being transferred from the inductor to the capacitor, the evil resistance (if any) continues to dissipate your precious energy.  Thus it is advantageous to keep this transfer time as short as possible.

This recovery scenario was described here.

[tinman]

Yes, but you have to be more precise when you write "give back".  For example, the energy stored in an inductor's magnetic field can be discharged into a capacitor. 
During the time while the energy is being transferred from the inductor to the capacitor, the evil resistance (if any) continues to dissipate your precious energy.  Thus it is advantageous to keep this transfer time as short as possible.

This recovery scenario was described here.

Should i say that the energy stored within the magnetic field is converted into another form when the magnetic field collapses. This conversion is 100% of the stored energy within the magnetic field.

[verpies]

With an ideal inductor discharged into an ideal capacitor - yes
...and if you count the heat dissipated in a resistance as just another form of energy, then the answer is yes even for non-ideal inductors.

[tinman]

Edit after verpies edit.
Cool,so all energy is accounted for when the field collapses

[tinman]

Yes, you could prove that, but not over an integer number of cycles.

How about just one continual cycle?