Simple question about generators... Please help

[Harry10]

i understand the concept about electric generators. i know it deals with rotating magnets and copper wires and an alternating current.

but what i don't understand is... where does the elecricty and electrons come from???... are electrons free floating in space and air?

sorry if this is a stupid question.

can somebody please help.

[NickCoons]

Everything naturally has electrons in it.  The electrons in metal atoms (like copper) float freely from atom to atom, such as along a wire.  When you generate electricity, what you are doing is converting one type of energy into another type.  Generating electricity is basically taking energy and using it to move electrons in a circle through a circuit.

So you're not making electrons or introducing new electrons into the circuit.. you're just taking the electrons that are already there and moving them in a circle through the device that you're powering.

[finnsawyer]

I'd like to add that the electrons in the copper wire, when they move through the magnetic field experience a force on them that causes them to pile up at one end of the wire or coil.  When an external load like a resistor is connected to the wire the electrons move through the resistor to the other end of the wire.  A current will flow as long as the motion continues and mechanical energy is converted to electrical energy as a result.

[troy]

Yup,

Like they said.  I have an old high school physics book with a nice illustration.  It compares copper wire (or any good conductor) to a pipe full of marbles with the pipe arranged in a complete circle.  The marbles are the electrons and they are there all the time.  The force of the magnets in the generator is just pushing the marbles around inside the pipe.  That's why you must have a complete "circuit" for the marbles/electrons to circulate because they don't want to leave the pipe and venture out into thin air.

HTH

troy