1. Electric Circuits Series and Parallel Circuits

2. Light a bulb  You are given: Wires, a bulb and a battery. Your job is to: Light the bulb.

3. To light a bulb, the most important thing is:  There must be a complete path, or NO GAPS. This is a CIRCUIT.

4. Electric Circuit  An electric Circuit is any path along which electrons can flow.  For a continuous flow of electrons, there must be no gap in the circuit.  An electric switch must be closed for electricity to flow.  There are two types of electric circuits: Series Circuits Parallel Circuits

5. Series Circuits  There is only a single path for electrons to flow.  Disadvantage: If one bulb fuses, the current in the circuit stops.

6. In a series circuit  The current through each bulb is the same.  The total resistance is the addition of all resistances.  The current in the circuit is equal to the battery voltage divided by total resistance.

7. Series Circuit  The total resistance in a series circuit is the SUM of all resistances.  Ex: The Total Resistance of two 8 Ω resistors connected in series is ____.  =  What is the total resistance of three 4 Ω resistors in series?  4+4+4 = 12 Ω

8. Parallel Circuits  Each bulb is connected to the battery terminals.  Each bulb operates INDEPENDENT of each other.  If one bulb fuses, it does not disrupt other bulbs.

9. In a parallel circuit  The voltage across each bulb is the same.  The total current in the circuit equals the sum of currents in all the branches.

10. Parallel Circuit  The Total resistance for a pair of equal resistors in parallel is HALF the value of either resistor.  Ex: The Total Resistance of two 8 Ω resistors connected in parallel is ___.  =  Ex: The Total Resistance of two 10 Ω resistors connected in parallel is ___.

11. Can I have three volunteers please?  How can they arrange themselves to form a series circuit?  How much current will flow through each?  How much voltage will be across each?  How can they arrange themselves to form a parallel circuit?  How much current will flow through each?  How much voltage will be across each?

12. Differentiate between  Series Circuit Only 1 path for current If one bulb fuses, current stops. Resistance of a series circuit is more Current in a series circuit is less Voltage is divided among all bulbs  Parallel circuit Multiple paths for current If one bulb fuses, others still work Resistance of a parallel circuit is less Current in a parallel circuit is more. Voltage across all bulbs is the same

13. For now Open to Pg 714 and answer Q 2, 3, 5, 6, 7, 8, 9 Next class, test on Electricity Next week – Physics Finals