Nodal Analysis

Purpose: 

Pre-lab: Use nodes method to find V1 and I1 in the circuit above:

As we found: I1 = 0.321 mA, V1= 5V since it is parallel with 5V source. 

During the experiment, we found V1= 4.98V, and I1= 0.320mA (I1, in this case, is calculated using V of DMM divides by 10k resistor.

Percent error of V1 = (| 4.98 - 5.00| / 5) x 100 = 10%

Percent error of I1 = (|0.320 - 0.321| / 0.321) x 100 = 0.31%

The reason for the high percent error of V1 because of the actual value of the resistor being used was 6.6k instead of 6.8k. There will be also a small error in current because of the value of the resistor was too small compared to the internal resistance of DMM.

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Purpose: In this lab, we also calculate and simulate the circuit to find the value of V1 and I1. 

Pre-lab: 

We used the mesh method to solve this problem. The actual value of resistors being used are 1.3k,  4.7k, 6.6k, and 21.7k. We calculated I1 = 0.288A, I2 = 0.927A, and I3 = 0.109A from the loop equations.  From values just found, we calculated the voltage goes through 1.3k and 21.7k resistors are 0.374V , 2.35V.

These values belove are what we got by using DMM to measure voltage across 1.3k and 21.7k resistor.

Percent error of current I1 = (|0.282-0.288)/0.288)x100 = 2.08%

Percent error of voltage V1= (|2.45-2.35|)/2.45)x 100 = 4.08%

There is a small percent error because of the value of resistors are too small compared to the internal resistor of DMM.