ELEC1111 - Electrical Circuit Fundamentals

Last modified by Leon Luo on 2022/10/31 14:08


This course is the UNSW's introductory course into the world of electrical engineering.


These concepts are studied through course content, mainly lecture notes and course recommended textbooks. Please note, unless referenced from another source, please assume the following information presented is interpreted, studied, and re-expressed from the course content. Furthermore, please refer to the course content directly, e.g. ask the lecturer or read the textbook, for the most relevant knowledge required for the course.


Electrical Engineering stems from the various discoveries and efforts of scientists from the past

Physics Basis

Electrical engineering stems from the physics of electromagnetism. Further introduction of electromagnetism is covered in  PHYS1231 and the engineering application of electromagnetism in ELEC3115.

The Systems of Units

The System of Units refers to the International System of Units which is usually abbreviated as SI. The SI system

The Electric Charge


Current by definition is the change in electric charge over the change in time. 

\begin{equation} i\triangleq\frac{dq}{dt} \end{equation}

Furthermore, the unit of current is amperes  \(\mathrm{A}\) which is defined as 1 coulumb per 1 second for 1 ampere.
\begin{equation} 1\mathrm{A}=1\frac{\mathrm{C}}{\mathrm{s}} \end{equation}

Common notations for currents in electrical engineering
\(I\) : Constant current
\(i(t)\) : Instantaneous or time-dependent current. It should be further noted that  \(i(t)\) can be simplified as \(i\) . However, this simplification can lead to confusion with complex numbers which uses \(i\) as the symbol for imaginary numbers. As a result, it is common to see the imaginary symbol, \(i\) , be represented as \(j\) in electrical engineering. In the context of ELEC1111 and ELEC2134, the use of \(j\) is highly preferred over use of \(i\) due to convention.

It is common in 


Resistance & Conductance


Basic Circuit Abstractions



Short & Open Circuits


Nodal & Mesh Analysis

Circuit Theorems

Capacitors and RC Circuits

Inductors and RL Circuits

Operational Amplifiers

AC Analysis

AC Power

Created by Leon Luo on 2022/08/01 21:28
CC BY-NC-SA 4.0 © Super ELEC 2022 All Rights Reserved.
By using this site, you agree to the Terms of use and Policies.
Please read the Disclaimers - This website uses XWiki and is not officially affiliated with UNSW.