# CH 1 – Basics

This chapter introduces the most essential concepts to understand electronic circuits. First in the row are physical quantities like electric charge, electric current, voltage and electric power. Next are some basic components like voltage sources, conductors, resistors, and switches. Finally the basic laws of electric circuits are discussed, with a lot of practical challenges to help understanding how these circuits behave.

## Chapter Objectives

1. Understanding the meaning of the basic physical quantities in electric and electronic circuits: charge, current, voltage and power
2. Knowing the current-voltage relationship of some basic components of electric circuits: voltage sources, conductors, resistors and switches
3. Analyzing electric circuits by making use of some fundamental laws: Ohm’s Law, Kirchhoff’s Current Law (KCL) and Kirchhoff’s Voltage Law (KVL)

Perhaps the most troublesome aspect of electric circuits is that a lot of phenomena cannot be observed directly. High electric currents can go through an electric wire, but these cannot be seen with the human eye. This makes electric circuits rather abstract, as opposed to e.g. mechanical systems. However, with some imagination these phenomena can be understood by making use of analogies. There are indeed some similarities between water going through a tube and electrons going through a wire.

Many textbooks focus on methodologies to analyze circuits. This is a worthwhile approach that should be understood by engineers but it has the disadvantage that it does not always lead to real understanding. Therefore, towards the end of the chapter, many challenges are presented to the reader that build up in complexity, and that intend to learn to analyze circuits by intuition. However, first things first, let’s introduce some basic concepts.

Go to 1.1 Electric Charge