Electric Currents

Electric Currents

• a path along which electrons flow

• must have no breaks in the path to work

• 2 types: – closed (no breaks)– open (break, causes

the device to shut off - switch)

1. electronic current

Electric Currents

2. 4 parts of a circuit

• energy source• load• wires• switch

Electric Currents

3. energy source

• pushes the electric charges through a closed circuit

• battery- has a positive and a negative terminal, one side repels electrical charges and one attracts

Electric Currents

4. load • the device the circuit delivers the energy to

• examples: light bulb, bell

Electric Currents

5. wires • connect the energy source to the load

• often copper, because it is a good conductor, wrapped in plastic insulation to keep the current from flowing to other conductors

Electric Currents

6. switch • opens and closes a circuit by bringing together or separating two pieces of metal

Electric Currents

7. potential difference

• the measure of how much energy is lost when electrons go through a load

• the work needed to move a charge from one point to another

• measured in volts

Electric Currents

8. voltage • amount of potential difference

• higher the voltage, the more energy the electrons have

• measured by a voltmeter

Electric Currents

9. current • the number of electrons per second that flow past a point in a circuit

• measured with an ammeter

• SI unit of measurement in the ampere or amp

Electric Currents

10. resistance

• the ability of the material to oppose the flow of electrons through it

• measured in ohms Ω• thin wire= more resistance

because there is less room for the electrons to travel

• longer wire= more resistance

Electric Currents

11. conductors

• materials that allow for free and easy movement of electrons

• metals are good conductors, especially copper, silver, and aluminum

Electric Currents

12. insulators • materials that are NOT good at carrying current

• examples: rubber, wood, glass

• the charge gets stuck and doesn’t move throughout the material