LAB #03: Nodal Analysis

OVERVIEW:
The purpose of this lab was to analyze, build, and test a circuit containing multiple sources. Our method for solving the circuit is nodal analysis.

PROCEDURE:
Pre-Lab:
As illustrated in the ENGR 44 Lab book, analyze the circuit in Figure 1 using nodal analysis to predict the values of V1 and V2.

Lab:

1. Construct the circuit; measure and record all actual resistance values. Measure V1 and V2 in the circuit.
2. Calculate the percentage error between your measured values and your predicted values for V1 and V2 respectively.

Physical Circuit (Zoomed In)

Physical Circuit (Zoomed Out)

ANALYSIS:
Pre-Lab:
Predicted Voltage Values:
Va = -0.602 V
V1 = 2.397 V
V2 = 4.397 V

Pre-Lab Calculations w/ Circuit Schematic

Lab:
Part 1:
Actual Resistance Values:

R1 = 9.9 k
R2 = 21.7 k
R3 = 6.6 k

Actual Voltage Values:
V1 = 2.38 V
V2 = 4.35 V

Measuring V2 (Sample)

V1 on DMM

V2 on DMM

Part 2:
Percent error between predicted and measured voltage:
Error in V1: (|2.397 - 2.38| / 2.397)* 100 = 0.709%
Error in V2: (|4.397 - 4.35| / 4.397)* 100 = 1.07%

CONCLUSION:
Our measured values for V1 and V2 are definitely within a reasonable margin of error. During the pre-lab, we used nodal analysis to predict the values of V1 and V2. We found these values to be 2.397 V and 4.397 V respectively. For the actual lab, we measured Vl = 2.38 V and V2 = 4.35 V. This corresponds to a percent error of 0.709% and 1.07%  for V1 and V2 respectively. This uncertainty is likely due to the internal resistance of the DMM.