I understand that coils have properties over a single wire in producing a magnetic field. But I'm a hobbyist not an expert. I know electricity was discovered from a wire carrying a charge when presented in a magnetic field. So I wonder if that is why we use wire and wire coils to pass through the magnetic field. (Because that's what was used at the time of discovery.)

Solid copper presents a massive magnetic field, as seen when dropping a strong magnet through the inside of a length of copper pipe.

Has anyone tried using solid copper plates to generate magnetic fields instead of coiled wire? Would that work or not? Why?

Coiled Wire vs. Copper Plate electrical generation

  • $\begingroup$ @Carl Witthoff, Why was the question changed? I wanted to know why wire coils are used to generate electricity. I understand and appreciate induction methods that generate their own magnetic fields, (induction motors and generators are awesome!) but magnetic fields are still used to generate electricity. Do all inductor rotors use wire windings? Or do some of them use copper plates shorted on the ends? $\endgroup$ Commented Mar 23, 2017 at 14:39
  • $\begingroup$ John, you asked about electricity in such a confusing manner that I guessed you wanted to know about the mag field. If you wanted to know how to induce a current in a wire (hardly what one might call "electricity"), then please reword accordingly. $\endgroup$ Commented Mar 23, 2017 at 15:14
  • $\begingroup$ Ok, I think I understand. As a layman I must have a misunderstanding of what electricity is exactly. But I have seen electricity generated by cranking one of the simple generators in the photo above, at least enough to cause an incandescent bulb to glow. Albeit, you need to crank the heck out of it. Isn't generating a current and voltage through a coil also generating electricity? $\endgroup$ Commented Mar 23, 2017 at 18:25

2 Answers 2


The current generated by a conductor moving through a magnetic field is related to the length of the conductor and the magnetic field strength.

A coil is simply a convenient way to get a longer length of conductor within a given space. The cross sectional area doesn't actually matter in terms of generating power except insofar as it determines the current carrying capacity of the wire.

It looks like you've slightly misunderstood the configuration of the winding of a motor or generator as one complete loop from N to S is one turn of the coil, you don't just make one leg of the loop into a coil. See this question on the electrical site for a good diagram.

  • $\begingroup$ So length is more important than mass. And since it is coiled it can produce a much higher magnetic field than a single conduit like a solid copper plate. The diagram is a simplification of course. Generators have several coils pointed at south poles while their other ends are facing north poles. But the basic generation of electricity is a loop of copper/silver between north and south poles, isn't it? cdn4.explainthatstuff.com/dc-generator-ac-alternator.png $\endgroup$ Commented Mar 22, 2017 at 13:00

They are also used in transformators for changing an ac voltage to another value by inducing a current without any metal parts touching each other, just by the coils’ magnetic field. IE=EI

İn your question it would work but the coils would generate more magnetic field because they have turns.


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