1. Electric
Circuits

2. How you should be thinking about electric circuits:
Resistance: friction that impedes flow of current through the circuit (rocks in the river)

3. How you should be thinking about electric circuits:
Current: the actual “substance” that is flowing through the wires of the circuit (electrons!)

4. circuit diagram
Scientists usually draw electric circuits using symbols.
cell
lamp
switch
wires

5. What is the difference between open and closed circuits?

6. Circuit:
A closed-loop path of conduction through which an electric current flows

7. An incomplete path that will not permit an electric current to flow
Open circuit:
An incomplete path that will not permit an electric current to flow

8. A complete path for electric current
Closed circuit:
A complete path for electric current

9. What kind of circuit is this?
closed
Open circuit?
Closed circuit?

10. What kind of circuit is this?
Open- the switch is open!
Open circuit?
Closed circuit?

11. There are two main types of circuits:
Parallel
Series
and

12. Parallel circuits are circuits with more than one pathway through which electrons can flow.
Series circuits are circuits with only one pathway through which electrons can flow.

13. Series and Parallel Circuits

14. What type of circuit is shown here?
Holiday lights
series
Parallel?
Series?

15. What type of circuit is shown here?
Car headlights
parallel
Parallel?
Series?

16. Series
Duracell
open
Open or closed circuit?

17. Series
Duracell
closed
Open or closed circuit?

18. Parallel
Duracell
Open because the switch is open

19. Parallel
Duracell
Closed- all lights are lit