Push a magnet into a coil and a meter flicks, even though no battery is anywhere in sight. The moving field alone conjures a voltage. Stop moving it and the voltage vanishes at once.
Moving a conductor across a magnetic field, or changing the field through a coil, induces an e.m.f. The induced e.m.f. is larger when the movement is faster, the field stronger, or the coil has more turns. Reversing the motion reverses the induced current.
Electromagnetic induction is the inducing of an e.m.f. when a conductor cuts magnetic field lines, or when the magnetic field through a coil changes.
A stationary magnet inside a coil induces nothing. The field must be changing. Reversing the motion reverses the induced current.
Move a magnet in and out of a coil and see the induced e.m.f. respond to the speed and direction.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
An e.m.f. is induced in a coil when...
Moving the magnet faster into the coil induces...
Using a coil with more turns gives...
A magnet held perfectly still inside a coil induces...
The induced e.m.f. depends on how fast the field changes, how strong it is, and how many turns the coil has.
An e.m.f. is induced only while the field through the coil is changing. A magnet held still inside a coil induces nothing. It must be moving, or the current switching, for induction to happen.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
A magnet is pushed into a coil, inducing a current one way. When the magnet is pulled back out, the current...
Which change would increase the e.m.f. induced as a magnet moves into a coil?
A bar magnet rests motionless inside a coil connected to a sensitive meter. The meter reads...
Electromagnetic induction is mapped. Keep the chain going.