8.2 Electric Current
A complete pathwaythat allows electronsto flow is called anelectric circuit
Any device thattransforms electricalenergy into otherforms of energy iscalled an electric load
Examples: lightbulbs, buzzer,heater, motor
4 basic parts
Source - the source of electrical energy (ex.Battery)
Conductor – wires through which electric currentflows
Load – device that transforms energy
Switch – a device that can turn the circuit on or offby closing or opening the circuit
Circuit diagrams use symbols to represent thedifferent components of the circuit
Draw your diagrams with a ruler
Make all connecting wires and leads straight lines withright 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 thepositive terminal of the battery
Continuous flow of charge in a complete circuit is calledcurrent electricity
Electric current – the amount of charge passing apoint in a conductor every second
Measure in amperes (A) in honour of French physicistAndre-Marie Ampere
Small currents are measured in milliamperes (mA)
An ammeter is used to measure the current in a circuitand it’s symbol looks like:
Historically they thought charge flowed frompositive to negative (the opposite of what we nowknow to be true) and this is called conventionalcurrent