1. Series Circuit What is a Series Circuit? Series Circuit Series Circuit – all parts are connected in a single loop (only one path).

2. Series Circuit What is a Series Circuit? Battery Load Switch

3. Series Circuit Battery Load Switch Do the loads work when the switch is open?

4. Series Circuit Battery Load Switch Do the loads work when the switch is closed?

5. Series Circuit Battery Load Switch If the battery is 9 V and the loads (light bulbs) are 3 Ω each, what is the current? (Remember, V = IR)

6. Series Circuit Battery Load Switch If the battery is 9 V and the current is 3 amps (A), what is the power? (Remember, P = VI)

7. Series Circuit Battery Load Switch If a 4 th load (light bulb) is added, what is the resistance of the circuit? (Remember, each load is 3 Ω) Load

8. Series Circuit Battery Load Switch What is the new current of our new circuit? (Remember, V = IR; V = 9 V and R = 12 Ω) Load

9. Series Circuit Battery Load Switch What is the power to each load (light bulb)? (Remember, P = VI; V = 9 V and I = ¾ A) Load

10. Parallel Circuit What is a Parallel Circuit? Parallel Circuit Parallel Circuit – different parts (loads) are located on different loops (more than one path).

11. Parallel Circuit Battery Load Switch See how the lines (conductors) going to the loads form parallel lines?

12. Parallel Circuit Battery Load Switch Do the loads work when the switch is open?

13. Parallel Circuit Battery Load Switch Do the loads work when the switch is closed?

14. Parallel Circuit Battery Load Switch If the battery is 9 V and the loads (light bulbs) are 3 Ω each, what is the current to each load? (Remember, V = IR)

15. Parallel Circuit Battery Load Switch What is the power at each load (light bulb)? (Remember, P = VI; I = 3 A and V = 9 V)

16. Parallel Circuit Battery Load Switch If a 4 th load is added to the circuit, what is the current to each load? (Remember, V = IR; V = 9 V and R = 3 Ω) Load

17. Parallel Circuit Battery Load Switch What is the power at each load (light bulb)? (Remember, P = VI; I = 3 A and V = 9 V) Load

18. Summary Adding loads in series reduces the current, which reduces the power to each load (if it were a light bulb, each bulb would be “dimmer.” (9 watts with 3 bulbs and about 7 watts with 4 bulbs) Adding loads in parallel has no effect on the current to each load, and thus, has no effect on the Power to each load! (27 watts to each bulb)

19. Circuit Safety What would happen if the insulation of a wire wore out? Short circuits and overloads can cause fires! Thus, circuits are protected with fuses and circuit breakers