Magnetism - invisible lines of force
In magnets the lines always travel from North to South
HOWEVER
In the Earth the lines travel from South to North
The magnetic materials are
Iron
Nickel
Cobalt
Electricity - the flow of electrons along a conductor
Voltage - measure of "electrical energy" (measured in volts)
Voltage doesn't define the amount of energy!
Current - the rate of flow of electrons (measured in ampere/amps)
Resistance - measure of how much the flow is prevented (measured in Ohm)
The Ohm's law:
V = IR
Therefore:
I = V/R
R = V/I
V: Voltage
I: Current
R: Resistance
