8.2 Electric Current

A complete pathway that allows electrons to flow is called an electric circuit Any device that transforms electrical energy into other forms of energy is called an electric load Examples: light bulbs, buzzer, heater, motor

 4 basic parts  Source - the source of electrical energy (ex. Battery)  Conductor – wires through which electric current flows  Load – device that transforms energy  Switch – a device that can turn the circuit on or off by closing or opening the circuit

 Circuit diagrams use symbols to represent the different components of the circuit  Draw your diagrams with a ruler  Make all connecting wires and leads straight lines with right angle corners  Do not let conductors cross over one another

Electrons are pushed from the negative terminal of the battery, along conducting wires through a load and end up on the positive terminal of the battery Continuous flow of charge in a complete circuit is called current electricity

 Electric current – the amount of charge passing a point in a conductor every second  Measure in amperes (A) in honour of French physicist Andre-Marie Ampere  Small currents are measured in milliamperes (mA)  An ammeter is used to measure the current in a circuit and it’s symbol looks like:  Historically they thought charge flowed from positive to negative (the opposite of what we now know to be true) and this is called conventional current