Imagine a piece of metal wound in a solenoid connected to an AC generator, when the generator is turned on, edd currents are produced, and the metal is heated, why is it heated? And what energy is wasted?
Also, magnetic damping? If I drop a single loop into a magnetic field a force opposes the motion of the loop. Where does this force come from?
Thank you very muchh!
8. April 2010 at 8:42 pm
The metal has resistance, which converts electric energy to heat.
When you drop the loop into the field, it experiences a magnetic force:
F = q(v x B) where q is the charge, v is velocity, B is the magnetic field and the x is the vector cross product.
The charges move, which makes a current. The interaction of the current and the magnetic field creates a force opposite to the direction of motion. It’s easier if you try and draw a diagram and spend some time using the right hand rule:
http://en.wikipedia.org/wiki/Right-hand_rule
to work it out!