Electrical resistance is defined as the force that opposes to the flow of
electric current. Resistors are used to limit the flow of electric current in
the circuit.
According to Ohm's law, electric resistance is calculated with the formula
below :
Resistance = V (Potential Difference) / I (Electric current through the object)
SI unit of electrical resistance is ohm. Other common units are milliohm,
microohm, volt/ampere etc.