Lab 1 TF EIM

Kirchoff's Law (50 pnts)

Construct the circuit below.

Enter the values of the DC voltage and Resisters that you used.

Use a voltmeter to measure the potential difference and resistances.

Variable	Measured Value
[math]V_A [/math]
[math]V_B [/math]
[math]R_1[/math]
[math]R_2[/math]
[math]R_3[/math]

Enter the measured and predicted quantities in the table below

Use Kirchoff's laws to predict the Voltage ([math]V_C[/math]) and current values and compare them to your measurements by filling in the table below.

Variable	Measured Value	Predicted Value	% Difference
[math]V_C[/math]
[math]I_1[/math]
[math]I_2[/math]
[math]I_3[/math]

Internal resistance (30 pnts)

Measure the internal resistance of your power source by graphing the potential difference on the x-axis and the current on the y-axis for several values of the resistance [math]R_L[/math] shown in the circuit below. Begin with [math]R_L = 1k\Omega[/math] and then decrease it by a factor of 5 for each subsequent measurement. You can use a volt meter to measure the current and potential difference.

Questions (20 pnts)

1. What conservation law is involved in Kirchoff's Loop Theorem?
2. What does the slope in the internal resistance plot above represent?

Forest_Electronic_Instrumentation_and_Measurement