2. Warm-up: A light bulb with 100 ohms of resistance is connected to a 9 volt battery. How much current is running through the light bulb? Warm-up: A light bulb with 100 ohms of resistance is connected to a 9 volt battery. How much current is running through the light bulb? Warm-up extension: The power that the light bulb uses is equal to: Warm-up extension: The power that the light bulb uses is equal to:

4. Video Analysis: “National Lampoon’s Christmas Vacation” Video Analysis: “National Lampoon’s Christmas Vacation” Video Clip Video Clip When Mr. Griswald tries to turn on his Christmas lights, they do not light. Why do you think this happens? When Mr. Griswald tries to turn on his Christmas lights, they do not light. Why do you think this happens?

5. Series Circuit Circuit in which electrical current has only one path for the current to flow through.

6. CHARACTERISTICS OF SERIES CIRCUITS: Characteristic #1: As resistors are added in series, the total resistance increases causing the current to decrease.

7. Consequence of Characteristic #1 Recall yesterday that P = I*V Recall yesterday that P = I*V What happens to the power used by the circuit as more resistors are added to a circuit? What happens to the power used by the circuit as more resistors are added to a circuit? Would you consider this to be an advantage or disadvantage for a series circuit? Would you consider this to be an advantage or disadvantage for a series circuit?

8. Characteristic #2: The current is the same at all points in the circuit.

9. Characteristic #3: Each component uses part of the total potential available.

10. Parallel Circuit A circuit with more than one path for current to flow through.

11. Characteristic #1: As resistors are added in parallel to a circuit, the total current will increase. CHARACTERISTICS OF PARALLEL CIRCUITS:

12. TOO MANY PATHS = SHORT CIRCUIT!! More paths = smaller resistance = higher current

13. Consequence of Characteristic #1 Recall yesterday that P = I*V Recall yesterday that P = I*V What happens to the power used by the circuit as more resistors are added to a circuit? What happens to the power used by the circuit as more resistors are added to a circuit? Would you consider this to be an advantage or disadvantage for a series circuit? Would you consider this to be an advantage or disadvantage for a series circuit?

14. Characteristic #2: The total resistance for a parallel circuit decreases as each new resistor is added in parallel.

15. Characteristic #3: Each branch of a parallel circuit has the same voltage as the potential source.

16. Characteristic #4: The sum of the current in each branch is equal to the total current out of the power supply.