Magnet Myths and Misconceptions

[Qwert]

And it will be a revelation of 100G where 'G' stands for God.

I guess a good example to understand the concept of moving charge at DC while electrons only push their neighbors is the known "domino effect" where domino pieces represent electrons: they need only small movement to transfer energy along their path: more rows have more energy, also taller pieces have more energy: one stands for I, another one for V.

[vineet_kiran]

Strength of magnetic field produced by a coil depends on number turns also. 

Think that you have a superconductor wire at room temperature.  Make a coil with it having 'X' number of turns. Pass a DC of 'Y' amperes through it applying a voltage of 'Z'. The power input to the coil is 'YZ' watts.  Hence energy stored in magnetic field is also 'YZ' watts because coil is superconducting and no losses.

1) When number of turns is 'X',  input power is YZ and power of magnetic field is also YZ

2) Increase number of turns to '10X' adding additional wire, input power is 'YZ' and power of magnetic field is '10YZ'

3) Increase number of turns to '100X',  input power is 'YZ' and power of magnetic field is '100YZ'

4) Increase number of turns to 'infinite X',  input power is YZ and power of magnetic field is infinite!!  (coil is superconducting hence
    no resistance even with infinite turns)


Confusing....?

[poynt99]

Bill,

I don't believe there is any physical change in the wire from extended use. Sounds like a myth if some are saying there is.

[poynt99]

Strength of magnetic field produced by a coil depends on number turns also. 

That's academic, but what causes the field in a straight piece of wire?

Is it caused by the movement of the drift (free) electrons or the electron cloud in each atom? Or is it the alignment of the individual electrons to all "spin" with their axis' in the same plane?

[vineet_kiran]

That's academic, but what causes the field in a straight piece of wire?

Is it caused by the movement of the drift (free) electrons or the electron cloud in each atom? Or is it the alignment of the individual electrons to all "spin" with their axis' in the same plane?

May be it is same as the case of schrodinger's cat, dead and alive at the same time depending on circumstances  because for DC, electrons have to move but for AC,  electrons only have to vibrate in tune with the changing magnetic field causing vibration.

Don't know the exact reason. Some knowledgeable person has to explain.