Magnet Myths and Misconceptions

[MarkE]

@MarkE,

The point is not how magnet shape changes the magnetic field but how two magnets of identiclal shape and unequal strength attract an iron armature differently.

Two magnets with identical total magnetic field strengths:  M can have very different abilities with respect to picking up / holding soft iron pieces, IE your armatures.  By changing the winding permeability the field shape also changes.

[MarkE]

Is not all the P/in disipated as heat in an inductor being supplied with a DC current?. I mean,it dosnt require power to maintain a magnetic field,as the field can do no useful work,and a PM dose not require any power input to maintain it's field.The resistance of the coil,and the amps to the coil tells us how much power we are using,so it's all accounted for.This means that it takes no power to create and maintain the actual magnetic field,as all power in is disipated as heat.

In a DC E/M where nothing is moving, any energy dissipated is in the coil resistance.  When an armature moves energy is conveyed to the armature, and that energy comes from the power supply.  The armature's movement induces a BEMF on the E/M's coil.

[MarkE]

In fact,thinking about my last statement,i believe i can prove that a permanent magnet can/is doing useful work.

Want to run with me on this one MarkE?-work together on proving that a PM can/is doing useful work.

P.S-we can do it useing your very well loved physics.

You are welcome to try.  But maybe this little piece of information will be helpful to you:

Given two identical solenoids, one with the armature held stationary and the other where the armature moves against a spring, if we exercise the coil with the unlocked armature and derive the rms current and then apply that rms current to the solenoid with the locked armature, the solenoid with the locked armature gets considerably hotter.

[Pirate88179]

What about a piezo disk stuck between two neos?  Will not the constant squeeze release some measurable output?

Bill

[tinman]

You are welcome to try.  But maybe this little piece of information will be helpful to you:

Given two identical solenoids, one with the armature held stationary and the other where the armature moves against a spring, if we exercise the coil with the unlocked armature and derive the rms current and then apply that rms current to the solenoid with the locked armature, the solenoid with the locked armature gets considerably hotter.

Ok ,lets make this as simple as possable.
When we supply a DC current to a solenoid,is any of that input power used/consumed to create the magnetic field around that solenoid?