# Understanding Electromagnetic Waves: Maxwell's Equations and Wave Equation

14. Maxwell's Equations and Electromagnetic Waves I 🔗

## 00:00 - Chapter 1. Background

In this lecture, the professor begins by addressing administrative matters and confirms that an equation sheet will be provided for the midterm. He then delves into Maxwell's equations, emphasizing their significance and discussing their implications. The professor explains each equation and its implications, highlighting the relationship between electric and magnetic fields. He also mentions the wave equation and the anticipation of its revelation to the students.

## 04:43 - Chapter 2. Review of Wave Equation

The video discusses the wave equation using the example of a string under tension. The equation governing the behavior of the string is derived using Newton's laws and the Lorentz force equations. The tension in the string is analyzed by resolving forces and making approximations for small angles. The resulting wave equation is derived and its solution is shown to represent waves propagating at a velocity determined by the tension and mass per unit length of the string. The general solution to the wave equation allows for functions of x-vt, indicating waves moving to the right, and x+vt, indicating waves moving to the left. This demonstrates the fundamental concepts of wave propagation and the behavior of wave equations.

## 20:01 - Chapter 3. Maxwell's Equations

The video discusses Maxwell's equations and electromagnetic waves. The professor explains the conditions that a solution for the electric and magnetic fields must satisfy in order to adhere to Maxwell's equations. He emphasizes the importance of verifying these conditions for various surfaces and loops, and demonstrates how the equations can be satisfied for infinitesimal surfaces. The video concludes with the derivation of the wave equation, revealing that electromagnetic waves propagate at the speed of light.

## 56:47 - Chapter 4. Light as an Electromagnetic Wave

The video discusses Maxwell's equations and electromagnetic waves. It explains that light is simply electromagnetic waves consisting of electric and magnetic fields. The speaker shows how general wave equations can be obtained by taking the most general electric and magnetic fields. The video also delves into the relationship between the electric and magnetic fields, the conditions for electromagnetic waves to propagate, and the characteristics of the electric and magnetic fields in an electromagnetic wave. The speaker emphasizes the interplay between experimental observations and theoretical reasoning in understanding the nature of electromagnetic waves.