E LECTRICAL PRINCIPLES

W HAT IS ELECTRICITY Electricity. It's everywhere. It's in your house, in the air, in your body! A current of electricity is a steady flow of electrons. When electrons move from one place to another, round a circuit, they carry electrical energy from place to place like marching ants carrying leaves. Instead of carrying leaves, electrons carry a tiny amount of electric charge. The charged particle can be either positive or negative. In order for a charge to flow, it needs a push (a force) and it is supplied by voltage, or potential difference. The charge flows from high potential energy to low potential energy. Current will only flow is there is a complete circuit between a source of high voltage and low voltage (electrical pressure). It is this electrical pressure or voltage that pushes the electrons and causes the movement. A circuit is a closed path or loop around which an electric current flows Resistance means how much something opposes current flow Electricity appears in two forms: alternating current(AC) and direct current(DC).

D IRECT CURRENT Direct current does not change directions The electron flow is always from the negative pole to the positive pole Direct current is almost always what is used inside of electronic devices to power the various internal components.

A LTERNATING CURRENT Alternating current does change direction ~the direction of current flowing in a circuit is constantly being reversed back and forth Flexibility in traveling long distances. Used for audio signals