Electric Current & Resistance

Electrical Circuits

AP Physics 1Mr. Kuffer

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

Refer to page 612… Chapter 20… Figure 20.22

16

17

18

19

20

21

22

23

24

Name _____________________________________________ Date _______________ Period __________

Objective: Apply Kirchhoff’s rules for circuit analysis to measure and calculate various currents, voltage drops, and resistances in a multi-loop circuit with multiple electromotive forces.

In Short: In the following two circuits:

- Build the circuit and measure Currents, Voltages and Resistances.- Calculate the currents through each branch of the circuits. - Compare your theoretical calculation to your experimental measure.

Prep and Construction of Circuit:

1. Choose three different resistors, as per the circuits on the next page. Using the supplemental chart, determine the values of the resistors and record the values in both tables below. Construct circuit 1… Then Circuit 2.

2. Review the proper method of connecting a voltmeter. Using the voltmeter, determine V1, V2, V3, and the voltage of the battery. Record the values of potential difference in Table 1. Refer to Multi-meter PP as necessary.

3. Review the proper method of connecting an ammeter in a circuit. Connecting it incorrectly may result in broken equipment. Measure the current flowing out of the battery, and after each resistor. (Like with the last lab, this may require rearranging the circuit with different wires. Make sure you are measuring the current that you intend by tracing paths of conduction.) Record the values of current in Table 1. Refer to Multi-meter PP as necessary.

TABLE 1: Circuit 1 MEASURED data

Resistance (Ω) Voltage (V) Current (A)

1

2

3

Figure 1: Circuit 1

NOTE: the voltages you use will likely differ from the voltages in the two schematic diagram.

25

KIRCHHOFF’S LAWS LAB

4. Use the given resistance values and V from the above table to calculate the expected values of V1, V2, and V3, as well as I1, I2, I3, and Itotal. Show all work on the back of this sheet in proper problem solving format. Enter your results in Table 2 below.

TABLE 2: Circuit 1 CALCULATED data

Resistance (Ω) Voltage (V) Current (A)

1

2

3

Figure 2: Circuit 2

TABLE 3: Circuit 2 MEASURED data

Resistance (Ω) Voltage (V) Current (A)

1

2

3

5. Use the given resistance values and VB from the above table to calculate the expected values of V1, V2, and V3, as well as I1, I2, I3, and Itotal. Show all work on the back of this sheet in proper problem solving format. Enter your results in Table 2 below.

TABLE 4: Circuit 2 CALCULATED data

Resistance (Ω) Voltage (V) Current (A)

1

2

3

26

Notes:

27