1. Electric Current

2. Electric current Electric current is the rate of electron flow past a specific point in the circuit (how fast electrons pass through a point in the wire). The symbol for electric current is I. The units of electric current is amperes or amps (A).

3. Electric current DC

4. Electric current AC

5. Electric current can be compared to the flow of water.

6. Electric current can be compared to water current: ComparisonWater CurrentElectric Current Conductor What is flowing Units for flowing particles Time interval Rate of flow (current) pipe or hosewire water moleculeselectrons Litres (L) of water Coulombs (C) of charge (1 C = amount of charge on 6.25x10 18 electrons) per second (s) litres per second coulombs per second 1 ampere (A) = 1C/s

8. AMMETERS are used to measure the ________________ in a circuit. electric current How to use an AMMETER

9. I1I1 I0I0 I 0 the current coming from the power source. I 1 the current passing through the bulb. Example:We want to measure the current at I 0 and I 1 for the circuit below. I1I1

10. To measure the current at I 0 or I 1, the circuit must be _________________ to make the ammeter part of the circuit. The ammeter is then connected in _____________. disconnected How to use an AMMETER series

11. Connect the terminal of the ammeter to the wire(s) leading to the ___________________terminal of the power source. positive / red How to use an AMMETER positive / red

12. Connect the terminal of the ammeter to the wire(s) leading to the ___________________terminal of the power source. negative / black How to use an AMMETER negative / black

13. How to use an AMMETER I1I1 To measure I 0 :

14. How to use an AMMETER I1I1 To measure I 1 :

15. How to Read an AMMETER

16. What is the reading on this ammeter? If you connected the circuit to the 3A setting on the ammeter, then the current reading is 1.5 A. If you connected the circuit to the 1A setting on the ammeter, then the current reading is 0.5 A.

17. How to Read an AMMETER What is the reading on this ammeter? If you connected the circuit to the 3A setting on the ammeter, then the current reading is 2.15 A. If you connected the circuit to the 1A setting on the ammeter, then the current reading is 0.72 A.

18. How to Read an AMMETER What is the reading on this ammeter? If you connected the circuit to the 300 mA setting on the ammeter, then the current reading is 215 mA.

19. Electric Shock