LAB #06: Mesh Analysis II

OVERVIEW:
The purpose of this lab was to analyze, build, and test a circuit with multiple sources. Once again, we will solve the circuit using mesh analysis.

PROCEDURE:
Pre-Lab:
As illustrated in the ENGR 44 Lab book, we will analyze the circuit in Figure 1 using mesh analysis techniques to determine the mesh currents; and predict the voltage differences V1 and V2 using those mesh currents. Please note that this is essentially the same circuit used in my Nodal Analysis II lab.

Lab:

1. Construct the circuit; measure and record all actual resistance values. Measure V1, V2, and I1 in the circuit.
2. Calculate the percentage error between your measured values and your predicted values for V1 and V2 respectively.

Actual Circuit Built

ANALYSIS:
Pre-Lab:
Predicted Voltage Values:
V1 = 4.999 V
V2 = 1.224 V

Predicted Current Values:

i1 = .0604 mA
i2 = I1 = -0.3208 mA
i3 = -1.056 mA

Pre-Lab Calculations w/ Circuit Diagram

Lab:

Part 1:
Actual Resistance Values:

R1 = 20 k
R2 = 4.7 k
R3 = 10 k
R4 = 6.8 k

Actual Voltage Values:
V1 = 4.98 V
V2 = 1.23 V

Actual Current Values:
I1 = -0.366 mA
i1 = 0.066 mA

i1 on DMM

Part 2:
Percent error between predicted and measured voltage:
Error in V1: (|4.999 - 4.98| / 4.999)* 100 = 0.380%
Error in V2: (|1.224 - 1.23| / 1.224)* 100 = 0.490%

CONCLUSION:
Our measured values for V1 and V2 are definitely within a reasonable margin of error. During the pre-lab, we used mesh analysis to predict the values of V1 and V2. We found these values to be 4.999 V and 1.224 V respectively. For the actual lab, we measured Vl = 4.98 V and V2 = 1.23 V. This corresponds to a percent error of 0.380% and 0.490%  for V1 and V2 respectively. This uncertainty is likely due to the internal resistance of the DMM.