Electromagnetic induction - a.c. generator Flashcards
What is electromagnetic induction?
The process of generating electricity from motion
What happens when a coil of wire and a magnet move relative to each other?
Dynamo effect: a voltage is induced across the ends of the wire
What happens when the coil moving relative to the magnet is part of a complete circuit?
An induced current flows around the circuit
Why is an e.m.f induced in the coil when it moves relative to the magnet?
The magnetic field lines of the magnet are cut by the coils
What rule is used to find the direction of the induced current on the wire?
Fleming’s right hand rule
What does the thumb show?
The direction of motion
What does the index finger show?
Direction of the magnetic field - north to south
What does the middle finger show?
Drirection of induced current
What is Lenz’s law?
An induced current always flows in such a way that its magnetic field opposes the change that causes it
