What is meant by the terms AC, DC and frequency?
Electricity is said to flow when electrons in a suitable material (a “conductor”) are induced to move in a particular direction when a suitable force (an “electromotive force” or EMF) is applied to the material. This flow of electricity is called an electrical current and is measured in terms of amperes (usually shortened to amps). The EMF is measured in terms of volts. Direct Current (DC) electricity is the easiest to visualise because here the electrons (the electrical current) always move in the same direction. A battery is the EMF source most commonly used to produce small amounts of direct electrical current. For example, the common torch uses a battery as the EMF source. Electrical current flows from one side (e.g. the positive side) of the battery, through the element in the torch bulb (in the process heating the element to produce light) and completes the circuit back to the other side (e.g. the negative side) of the battery. Alternating Current (AC) electricity can be thought
