Def: Electricity is a form of energy
Electricity is the flow of charge. | |
All electrical devices in our homes change electricity from one form to another. | |
A battery provides the difference in electrical pressure necessary to drive electricity round a circuit. | |
Electric pressure is called potential difference and is measured in volts (V) | |
The volt is named after Alessandro Volta |
Electricity will flow if there is potential difference and a complete circuit. |
If energy is used in passing electricity through an object, that object is a resistor. | |
The unit of resistance is the ohm. | |
Electrical energy is changed to heat energy in a resistor |
Def: An electrical current is the flow of electrical charge.
Electric current is measured in amperes (amps). | |
To measure electric current we use an ammeter. | |
Andre Ampere was a French physicist who demonstrated that electrical currents produce magnetic fields. | |
Series Circuits: Bulbs connected in series are connected one after another. |
Parallel circuits: Bulbs connected in parallel are side by side in a circuit. (e.g. house lights) | |
Current flows from + to -. | |
The long line = positive | |
The short line = negative | |
Ammeter always connected into a circuit in series. | |
A voltmeter is always connected into a circuit in parallel. |