2.  Electric Current- net movement of electric charges in a single direction ◦ Example- powering electronics

3.  Electric Circuit- a closed path through which electrons flow ◦ Electrons flow because of difference in potential  Example- battery, lightbulb, and wire

4.  Electrons always flow from where there are more electrons (high potential) to where there are fewer electrons (lower potential)

5.  Battery- a device that maintains the difference in potential ◦ Supply energy to keep the electrons moving; doesn’t supply the electrons  Types ◦ Dry-cell (AA battery in remote) ◦ Wet-cell (car battery)

6.  Cell- consists of one positive electrode and one negative electrode surrounded by material called an electrolyte ◦ Electrolyte- a paste that enables charges to move from one electrode to another

7.  Wet Cell- Two connected plates (one positive and one negative) in a liquid conducting solution (electrolyte) ◦ Several wet cells connected together ◦ Car battery

8.  Resistance- the tendency for a material to resist the flow of electrons and convert electrical energy to other forms of energy ◦ Resistors are used to reduce the flow of a current through all or part of a circuit  Help protect more delicate electronic components  Example- used to computers

9.  Resistors transfer energy into other forms ◦ Light bulb- thermal, light  Resistance- measured in ohms (  )  All materials have some resistance, even copper wiring

10.  As temperature increases, resistance increases  As a material becomes longer (wire), resistance increases  As material becomes thinner, resistance increases

11.  Electric Current- flow of electrons in a single direction; path of electrons ◦ Measured in Amps (A)- Ammeter ◦ Depends on the amount of electrons that pass through every second  1 Amp- 6,250 million electrons per second ◦ Flow from negative voltage to positive voltage

12.  Voltage Difference- The difference in potential (the energy of the electrons) between two different places ◦ Measured in Volts (V)- voltmeter ◦ It’s the pressure that pushes electricity through a conductor (wire)

13.  Ohm’s Law- the current in a circuit equals the voltage difference divided by the resistance ◦ Current (I) measured in Amps ◦ Voltage difference (V) measured in volts ◦ Resistance (R) measured in ohms

14.  As the resistance increases, the current decreases  If the voltage difference in a circuit is greater, the current increases

15.  The voltage difference in a graphing calculator is 6V, and the resistance is 1,200 . What is the current through the batteries of the graphing calculator?

16. ◦ I=V/R ◦ I= 6V/1200  ◦ I= 0.005A

17.  The current through a circuit is 0.0030 A. What is the resistance of this circuit if the voltage difference across the circuit is 12V? ◦ I=V/R

18.  The current through a circuit is 0.0030 A. What is the resistance of this circuit if the voltage difference across the circuit is 12V? ◦ I=V/R ◦ 0.0030A= 12V/R ◦ R= 4000 