Dc Electrical Circuit Analysis Enb103

Queensland University of Technology

Electrical – ENB103 – Assessment 1

DC Electrical Circuit Analysis – Part A

Name: Mark Lowik

Student Num. N7206267

Due Date: 28th August, 5pm

Table of Contents

Introduction 3

1.0 Mesh Analysis 4

1.1 Determining mesh currents 4

1.2 Determining Nodal Voltage 5

1.2.1 Node A 5

1.2.2 Node B 6

2.0 Thevenin’s Theorem 6

2.1 Application of Thevenin’s Theorem 6

3.0 Comparing and Analysis of Results 9

3.1 Results 9

3.2 Analysis 9

Introduction

The purpose of this assignment is to analyse a DC circuit provided and ascertain certain properties within the circuit. To do this will require the application of Mesh Analysis, Thevenin’s Theorem and simple DC Theory...

1.0 Mesh Analysis

Applying mesh analysis to the circuit will determine the currents that flow through each of the three meshes provided. From these current values, simple DC theorem will be applied using Ohm’s law in order to calculate the voltage of node A and node B with respect to the ground node.

1.1 Determining mesh currents

The following steps will outline what will be required to calculate mesh 1, 2 and 3 currents.

1. Observing the circuit, use Kirchhoff’s voltage rule to determine each mesh into a formula resulting in three separate formulas.

Mesh 1

20(i1-2) + 20(i1-i3) + 50(i1-i2) = 0

90i1 - 50i2 - 20i3 = 40

Mesh 2

50(i2-i1) + 25i2 + 26 = 0

-50i1 + 75i2 = -26

Mesh 3

30i3 – 25 + 20(i3-i1) = 0

-20i1 + 50i3 = 25

2. Once completed simplify each formula by dividing by 10 in order to make calculations much simpler.

Mesh 1

9i1 - 5i2 – 2i3 = 4

Mesh 2

-5i1 + 7.5i2 = -2.6

Mesh 3

-2i1 + 5i3 = 2.5

3.

4. After that, construct a 3x3 matrix only using values of i1, i2 and i3. Using the resultant answer values, construct a 3x1 matrix.

4-2.62.5

5. From this, calculate the determinate of the original 3x3 matrix defining it as i.

∆i

9-5-2-57.50-305 =

9[(7.5x5)-(0x0)] – (-5)[(-5x5)-(0x-2)] +...