Series Circuit Lab

Series Circuit Lab

Name______

Objective: The objective of this lab is to able to calculate and measure equivalence resistance, current, and voltage drops across electrical devices connected in series.

Materials: Multimeter, 5 alligator ended connecting wires, 9 V battery

Use your multimeter to get the actual resistance.

3 Resistors: R1 = Grey Red Brown Gold = ______Ω R2 = Blue Grey Brown Gold = ______Ω

R3 = Brown Red Red Gold = ______Ω

Procedure:

1. Construct the circuit shown at the right.

2. Measure the voltage of your 9V battery. Make sure your multimeter’s probes

are plugged into the correct holes and the dial is set to the proper setting.

Vbattery = ______

2.5. Calculate the theoretical current flowing through the circuit using V = IR.

Current = ______

3. Close the switch and activate the circuit. Measure the voltage across R1, R2, and R3 with your multimeter. Make sure your red lead is connected to the positive side of your resistor. You will know you’ve measured correctly because you’ll have

a positive voltage. See the schematic on how to measure.

VR1 = ______VR2 = ______VR3 = ______

4. What is the relationship between the voltage drop across the battery and the

voltage drops across the resistors?

5. Switch the settings on your multimeter to measure mA. Make sure the red probe

is plugged into the correct hole. Insert your meter into the circuit at each spot of your

circuit below and record the current reading.

A1 = ______A2 = ______A3 = ______A4 = ______

6. What is the relationship between all the current readings throughout your circuit?

6.5 Why do you think the current you measured isn’t exactly the current you predicted would flow through the circuit?

7. Add up the resistance values of R1, R2, and R3. We’ll call this value Requivalence, or the equivalence resistance.

Requivalence. = ______

8. Go to the box of resistors and find the resistor that is equal to

the equivalence resistance. Construct this new circuit.

9. Measure the voltage drop across Requivalence.

VR equivalence = ______

10. What do you notice about the voltage drop across the equivalent resistor? Is it

similar to any other voltage you’ve measured?

11. Measure the current running through the circuit.

Aequivalence = ______

12. What do you notice about the equivalence current? Is it similar to any other current you’ve measured?