1. Circuits Series vs Parallel

2. Electric Circuit Path of current flow As electrons move through a circuit, they transfer potential energy from the source to the device (load) Circuits must be a continuous path in order for electrons to flow (closed circuit) Any break in pathway stops electron flow (open circuit) Electrons flow from – to +

3. Schematic Diagrams Use symbols to show circuit

4. Series Circuit Loads connected end to end Each Electrons have only one path to travel electron must go through each load before returning to the source Same amount of charge passes through each resistor so I is same for all I is constant

5. Different Resistors Current is constant throughout The V across each resistor will be different for different resistors The total of the V of the circuit will be the sum of the V of each resistor V = V 1 + V 2 + V 3 The total resistance is the sum of the resistances of each load R EQ = R 1 + R 2 + R 3

6. About Series More resistance you add, greater the total resistance, the less current through the circuit Series wiring is easy and doesn’t use much wire One load out breaks circuit and it all goes out Total current is decreased by the addition of loads

7. Parallel Circuit Current splits to separate branches Each electron travels through only one load before returning to the source Only some of the electrons go through each path so current is split between paths Total current is sum of currents through each path I TOT = I 1 + I 2 + I 3

8. About Parallel V is constant in parallel circuit Total resistance is actually smaller than that of the individual resistors Requires more wiring Don’t all go out if one does No loss of brightness (V) across resistors

9. Example Two 100 Ω resistors are connected a) in series and b) in parallel to a 24V battery. What is the current through each resistor and what is the equivalent resistance of each circuit?