Electrical Theory: Understanding the Fundamentals

Electrical theory is the study of electricity, from its basic principles to advanced quantum mechanics. Dive deep into the world of electric charges, circuits, electromagnetism, and quantum electrodynamics.

The essence of scientific study lies in creating and refining theories — scientific explanations that help us understand the natural world around us. Electrical theory is a critical aspect of this scientific enterprise. It provides the foundation for our understanding of electricity and its interactions with matter. This article aims to answer the question, “What is electrical theory?” by exploring its key concepts and tracing the historical developments that have shaped our understanding of electricity today.

The Basics of Electricity

At its most fundamental level, electricity is the movement or presence of electric charge. It comes in two types, positive and negative, which attract each other and repel charges of the same kind. The flow of electric charge is what we typically refer to as electric current.

The building blocks of matter, atoms, contain both types of charges — positive protons in the nucleus and negative electrons orbiting it. In some materials, such as metals, the outermost electrons can move freely in a sort of stream we call electric current.

Source- https://www.freepik.com/free-photos-vectors/atomic-structure

Early Observations and Laws

Electrical theory has its roots in the early observations and experiments by scientists like Benjamin Franklin, Charles-Augustin de Coulomb, and Luigi Galvani. Their work helped establish some of the fundamental principles of electricity.

Benjamin Franklin, in the 18th century, contributed significantly to the understanding of electricity by proposing the single-fluid theory. According to his theory, electricity was a ‘fluid’ that could be transferred between objects, making them positively or negatively charged.

Charles-Augustin de Coulomb established the inverse-square law for electric forces in the late 18th century. Which states that the force between two charges is proportional to the product of their charges and inversely proportional to the square of the distance between them.

Ohm’s Law and Circuit Theory

In the 19th century, George Simon Ohm formulated Ohm’s Law, which is fundamental to circuit theory. This law states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance between them.

Circuit theory, an essential aspect of electrical theory, uses these fundamental laws to analyze and design electrical and electronic circuits. It focuses on how voltage, current, and resistance interact in an electrical network. Each providing the foundation for much of modern electrical and electronic engineering.

Electromagnetic Theory

The 19th century also saw the development of the electromagnetic theory by James Clerk Maxwell. Maxwell’s Equations, as they are now known, describe how electric charges and currents create electric and magnetic fields. They also explain how changing electric and magnetic fields propagate through space as waves — the phenomenon we know as light.

Source- https://en.wikipedia.org/wiki/Electric_charge

Maxwell’s theory is a classical field theory, providing a unified framework to understand both electricity and magnetism. It has been instrumental in the development of technologies like electric power, radio, and television.

Quantum Electrodynamics

In the 20th century, the development of quantum mechanics led to a new understanding of electricity at the microscopic level. Quantum electrodynamics (QED), a quantum field theory, describes how light and matter interact. It explains electromagnetic interactions in terms of particles called photons. Showing how these photons are absorbed and emitted by charged particles like electrons.

QED is a critical aspect of modern electrical theory, explaining phenomena like the photoelectric effect (the emission of electrons when light hits a material) and the behavior of semiconductors. Which form the basis for modern electronics.


So, what is electrical theory? It is a collection of models, laws, and principles that describe how electricity works, from the flow of electrons in a wire to the propagation of light through space. It encompasses a range of phenomena and spans multiple levels of description, from the macroscopic scale of electrical circuits to the microscopic world of quantum particles.

Electrical theory has evolved significantly over the centuries. It’s shaped by the contributions of many scientists and the development of new experimental techniques. Despite its long history, it continues to be an area of active research, with ongoing studies into phenomena like superconductivity and quantum computing. As our understanding of electricity continues to deepen, electrical theory will remain a critical pillar of modern science and technology. Have more questions about theory? Check out our article “Basic Electrical Theory: Questions and Answers” for more information on the basics of electrical theory.

Enjoy learning about electricity?