Fundamentals of Electrical Engineering

Interactive introduction to electricity, circuits and electronics

What is Electricity?

Electricity is the movement of electric charge through a conductor. In most materials, the moving particles responsible for electricity are electrons. Electricity powers almost every technology used in modern society: computers, lighting systems, electric motors, communication networks, and industrial machines.

Understanding electricity is the foundation of electrical engineering. Before building circuits or designing electronic systems, it is important to understand the basic physical concepts behind electrical phenomena.

Electricity can be compared to water flowing in pipes. Voltage is the pressure pushing the water, current is the flow rate, and resistance is the friction slowing the flow.

Ohm's Law

One of the most fundamental laws in electrical engineering is Ohm's Law. It describes the relationship between voltage, current and resistance.

V = I × R

  • V — Voltage (Volts)
  • I — Current (Amperes)
  • R — Resistance (Ohms)

Ohm's Law allows engineers to calculate unknown values in electrical circuits. For example, if the voltage and resistance of a circuit are known, the current flowing through the circuit can be calculated.

Ohm's Law Calculator

Enter any two values to calculate the third.