Lab #8: Basic Rules in Series Circuits & Parallel Circuits

Objectives:

Describe rules that the current and voltage drops obey in the series circuits.

Describe rules that the current and voltage drops obey in the parallel circuits.

Equipment:

1. Two 1.5-V batteries
2. One Ammeter
3. One Voltmeter
4. One 5-Ohm resistor
5. One 10-Ohm resistor
6. One Switch
7. Some wires

Procedure:

Diagram first before you hook up any circuit. Draw a table and record the results when you are doing the experiments.

Experiment A

1. Hook up a series circuit with two batteries, a 5-olm resistor, a 10-olm resistor and a switch using wires.

2. Measure the voltage drops between the 5-olm resistor and the 10-olm resistor once at a time and record as V1 and V2.

3. Measure the voltage drops between both of the resistors and record as V.

Experiment B

4. Hook up a parallel circuit with two batteries, a 5-olm resistor, a 10-olm resistor and a switch using wires.

5. Measure the current through the 5-olm resistor and the 10-olm resistor once at a time and record as I1 and I2.

6. Measure the total current flows from the battery and record as I.

Experiment C

7. Repeat step 4.

8. Measure the voltage drops between the 5-olm resistor and the 10-olm resistor once at a time and record as V1 and V2.

9. Measure the voltage drops between both of the resistors and record as I.

Analysis:

10. What is the relationship between V1, V2 and V in Experiment A?

11. What is the relationship between I1, I2 and I in Experiment B?

12. What is the relationship between V1, V2 and V in Experiment C?

13. Try to explain why the relationships exist.