This is one of the most famous electrical laws published by Dr George Ohm in 1826. It allows us to understand the relationship between the basic elements of an electric circuit, voltage current and resistance. Voltage is the pressure or potential driving current around a circuit. Current, as we saw a little earlier at Fig. 2.1 is the movement of electrons through a conductor and resistance is the opposition to that current flow. His law may be expressed as voltage is equal to current times resistance or expressed mathematically as:
Ohm’s Law Formula:
An electric fan heater was found to take 10 A when connected to the 230 V mains supply. Calculate the resistance of the heater element.