Basic Principles of Magnetic Fields — Lesson 2

This lesson covers the basic principles of magnetic fields, their sources, and how they interact with electric fields. It delves into the history of magnetic fields, starting from their discovery by Orsted in the 19th century, to the invention of the electromagnet by William Sturgeon. The lesson explains the concept of magnetic fields being dipoles and the absence of monopoles, unlike electric fields. It also discusses the Gauss law of magnetic flux, Ampere's law, and Faraday's laws. The lesson uses illustrative examples such as the use of a solenoid to generate a magnetic field and the introduction of an iron core to increase magnetic flux density.

Video Highlights

00:05 - Introduction
00:49 - Discussion on the sources of magnetic fields
04:22 - Explanation of Gauss law of magnetic flux
14:39 - Understanding Ampere's law and its application
21:22 - Introduction to electromagnets and their advantages
27:37 - Relation between magnetic fields and electric fields
28:06 - Explanation of Faraday's laws

Key Takeaways

- Magnetic fields are created by moving charges or electrical currents and are always dipoles.
- The Gauss law of magnetic flux provides the relation between magnetic fields and magnetic flux.
- Ampere's law states that the magnetic field in a space around a current-carrying conductor is proportional to the current serving as its source.
- The introduction of a core in an electromagnet can increase the magnetic flux density.
- Faraday's laws explain the interaction between magnetic fields and electric fields, stating that a change in magnetic field will induce an EMF in a coil.