Ohm's law states, that the current through a resistor, is directly proportional to the voltage across it. The ratio of the voltage across a component, to the current flowing through it, is defined as resistance.
Resistance restricts the flow of current through a component and converts the electrical energy to heat. Ohm's law can be used to determine current, voltage or resistance in a circuit, if two of the three quantities are already known.
Ohm's law allows us to calculate the current that will flow in a circuit, if we know the voltage that is being applied and the total resistance of the circuit.
A 12V power supply is connected to a cct. It the cct's resistance is 5 Ohms, how much current will flow through the cct?
R = V/I, Therefore I = V/R, = 12/5, = 2.4A