2. ELECTRICAL QUANTITIES

2.1. Voltage or potential difference

A light bulb uses energy from the electrons to produce light and heat.

The amount of energy that a generator can transfer to electrons depends on its voltage. This is measured in volts.

2.2. Measuring electric current

Electric current is the charge of electrons that flow through the cross-sections of a conductor every second.

Electric current is measured in amperes or amps in the International System or SI.

2.3. Electrical resistance: Ohm's Law

The Resistance of a material is equal to the voltage divided by the intensity of the electric current which travels throgh the material. This ratio, whic is called Ohm's Law, can be expressed as follows:

R = V / I

V = R x I

I = V / R

2.4. Electrical energy and power

Electrical energy

Electric energy is the energy that keeps the electrons of a circuit in motion. This energy is provided by a generator and consumed by one or more loads.

Electric power

The electric power of a load is the amount of energy that it can transform over a certain amount of time. Electric power is measured in watts or kilowatts. One Kilowatts equals 1000 watts.

P = V x I