Analyzing Parallel Circuits
Name: ____________________
Learning Target: Determine the voltage, current, and resistance in series circuits.
Draw a Parallel Circuit that includes a 10 V battery, R1 = 8 Ω, R2 = 8 Ω and R3= 4 Ω.
Definition of a parallel circuit:
Directions:
1. Setup a circuit similar to circuit schematic below.
2. For each scenario measure the voltage over each resistor using a voltmeter.
3. Measure the current at the end of the circuit, by inserting an ammeter.
4. Record the resistance in the table.
5. Calculate the power.
Circuit Scenario 1
Batt.
R1
+ V1
R1
R2
R2
V(V)
10
I(A)
R(Ω)
P(W)
Circuit Scenario 2
V(V)
10
Batt.
+ V1
R1
R2
I(A)
R(Ω)
P(W)
R1
R3
R2
Circuit Scenario 3
Make a circuit with 4 resistors in parallel. Draw a schematic of the circuit and determine the
information for the table below.
Batt.
V(V)
10
I(A)
R(Ω)
P(W)
R1
R2
R3
R4
Conclusion:
1. What is the relationship between the voltages across the individual resistors and the voltage across the
Power Supply?
2. What happens to an individual resistor’s current when more resistors are added?
3. How do you find the total resistance of a parallel circuit?
4. Why are parallel circuits used for household circuits?
PROBLEMS:
Given that:
R1 = 10Ω;
R2 = 20Ω;
R3 = 50Ω;
and R4 = 100Ω
Total Voltage of power supply = 100 Volts
1. Draw a schematic of a circuit with R1 and R2 in parallel, connected to the power source. Calculate the current
for each resistor and the total resistance.
2. Draw a schematic of a circuit with R1, R2 and R3 in parallel, connected to the power source. Calculate the
current for each resistor and the total resistance.
3. Draw a schematic of a circuit with R1, R2, R3 and R4 in parallel, connected to the power source. Calculate the
current for each resistor and the total resistance.
PARALLEL CIRCUITS
1.
Voltage
Current
Resistance
+
5 
60 V
-
10 
15 

20 

2. A 23 Ohm and a 17 Ohm resistor are connected in parallel to a 12 Volt power supply. Draw a
schematic diagram for the circuit and complete the chart calculations.
Voltage
Current
Resistance
3. A 12 Ohm, a 15 Ohm, and a 5 Ohm resistor are connected in parallel to a 30 Volt power supply.
Draw a schematic diagram for the circuit and complete the chart calculations.
Voltage
Current
Resistance