1. October 18, 2017
Parallel Circuit

2. Drill – Take out Lab Handout/Conclusion
What are your top 2 colleges you want to talk to at the College Fair today?
What is the equation to calculate:
Total current in a circuit?
Total Voltage?
Total Resistance (neglecting resistance of wires)?
Total Power?

3. Parallel Circuit

4. Homework = College Applications

5. October 23, 2017
Parallel Circuit

6. Drill – take out Drill Sheets from last week
Draw a circuit diagram of a circuit containing 3 lightbulbs connected in parallel. Draw the path of the current.
What happened when one lightbulb was unscrewed in the parallel circuit? Explain.

7. Parallel Circuit Lab – Part 2
As a class, we will:
Use color codes to determine resistance of each resistor.
Measure voltage across each resistor.
Measure total voltage across batteries.
Measure total current through circuit.
Individually, you will:
Calculate Req, I1, I2, I3, all power values.

8. Parallel Circuit Characteristics
Two or more paths for current to flow through.
If one path is opened, current will flow through all the other paths.
The flow of current is divided between each according to the resistance along each path (Ohm’s Law). 

9. Current Current is split between the paths.
Total current = sum of the currents through each path
Current through each path is determinate upon resistance in that path (Ohm’s Law).
IT = I1 + I2 + I3

10. Voltage
Voltage is the same across each component of the parallel circuit.
VT = V1 = V2 = V3

11. Resistance Equivalent Resistance Formula: 𝟏 𝑹𝒆𝒒 = 𝟏 𝑹𝟏 + 𝟏 𝑹𝟐 + 𝟏 𝑹𝟑
𝟏 𝑹𝒆𝒒 = 𝟏 𝑹𝟏 + 𝟏 𝑹𝟐 + 𝟏 𝑹𝟑
Equivalent resistance = amount of resistance that a single resistor would need to equal the overall resistance present in the circuit

12. Series vs. Parallel – Equivalent Resistance
Series = more overall resistance.
Parallel = less overall resistance.
Consider two means of connecting two new tollbooths - in series versus in parallel.
Series: increasing the total resistance and decreasing the car flow rate.
Parallel: decreasing the total resistance and increasing the car flow rate.

13. Summary: Series vs. Parallel
Current: IT = I1 = I2 = I3
Voltage: VT = V1 + V2 + V3
Resistance: Req = R1 + R2 + R3
Power: PT = ITVT = P1 + P2 + P3
Parallel
Current: IT = I1 + I2 + I3
Voltage: VT = V1 = V2 = V3
Resistance: 𝟏 𝑹𝒆𝒒 = 𝟏 𝑹𝟏 + 𝟏 𝑹𝟐 + 𝟏 𝑹𝟑
Power: PT = ITVT = P1 + P2 + P3

14. Homework
Finish lab handout + write conclusion