1. Current

2. Electric Circuit
An electric circuit is a complete path through which electricity travels.

7. Circuits Open Circuit: A circuit with any break in it.
Closed Circuit: A circuit with no breaks in it.

8. Current
Electric current (I) is rate at which charges flow through an area.
Current is what carries energy in a circuit.
SI unit: amperes (A) or coulombs/second (C/s)

12. Voltage

13. Voltage Voltage is a measure of electric potential energy.
Voltage is measured in volts (V)
Voltage is the power per amp of current that flows

17. Resistance

18. Resistance to Current
Resistance is the opposition presented to electric current by a material or device.
The SI units for resistance is the ohm (Ω) and is equal to one volt per ampere.

19. Resistance to Current Resistance is opposition to the flow of charge.
SI unit: volts/ampere (V/A) or ohms ()
Ohm’s Law : V = IR
Valid only for certain materials whose resistance is constant over a wide range of potential differences
Ohm’s law does not apply to all materials. For example, when using a tungsten filament flashlight bulb, the current does not double when the potential difference doubles. The resistance of the filament changes when more voltage is applied and more current flows though it.

20. Ohm’s Law

22. A toaster oven has a resistance of 12 ohms and is plugged into a 120-volt outlet. How much current does it draw?

23. A digital camera uses one 6 V battery
A digital camera uses one 6 V battery. The circuit that runs the flash and takes the pictures has a resistance of 3 ohms. What is the current in the circuit?

24. A hair dryer draws a current of 10 A when plugged into a 120 V outlet
A hair dryer draws a current of 10 A when plugged into a 120 V outlet. What is the resistance of the hair dryer?

25. A television runs on 120 volts and has a resistance of 60 ohms
A television runs on 120 volts and has a resistance of 60 ohms. What current does it draw?