Learning Intention: Learn about the things that affect electrical current

Success Criteria: Create electronically - not copy/paste - a diagram comparing an electrical circuit to a water circuit, also explaining how voltage and resistance affect current flow

One of the best ways to understand electrical circuits is to consider an analogy with a water circuit. There are a number of ways to think about this

Electrical units and symbols

Learning Intention: Learn the units and symbols used to represent current, voltage and resistance

Success Criteria: Add info about the units and symbols for current, voltage and resistance to your Electrical Circuits sub-page

Voltage - measured in volts (v), symbol = V 

The force that excites the electrons to "flow" in a circuit is called voltage. Voltage is a specific measure of potential energy between two points. Talking about the presence of voltage in a circuit, we are referring to the amount of electrical force or how much potential energy exists to move electrons from one particular point in that circuit to another particular point. Without reference to two particular points, the term "voltage" has no meaning. 

Resistance - measured in Ohms (omega, last letter in the Greek alphabet), symbol = R 

The opposition to movement of free electrons in conductors is properly called Resistance. Electrical resistance is measured in a unit called Ohms. The amount of current in a circuit depends on the amount of voltage available to motivate the electrons, and also the amount of resistance in the circuit to oppose electron flow. Like voltage, resistance is a quantity relative between two points. For this reason, the quantities of voltage and resistance are often stated as being "between" or "across" two points in a circuit.