Before you read this, I suggest you read post 25.13. Electromagnetic induction arises when a current flows in a circuit when it is in a changing magnetic field (post 25.13). Faraday considered that the current flowed because an induced voltage caused charges in the circuit to move. Moving charges are an electrical current (post 17.44).… Continue reading 25.14 Electromagnetic induction and fields
I have written about the discovery of electromagnetic induction by Faraday in post 18.21. This earlier post was about inductance in an electrical circuit. Now I want to concentrate on the phenomenon of induction itself. Like Heaviside, Faraday had never attended university but made many important discoveries in chemistry and physics working at the Royal… Continue reading 25.13 Electromagnetic induction
Before you read this, I suggest you read posts 25.9 and 25.11 In 1865, the Scottish physicist Maxwell published a series of differential equations that described the properties of electromagnetic fields. But he had published several previous papers on the subject while he was developing his ideas. Maxwell derived over 20 equations to express his… Continue reading 25.12 Differential form of Gauss’s law
The purpose of this post is to introduce three properties of the sphere that I hope to use in future posts. A sphere has a constant radius, R. The three properties that I want to explain are The first might be difficult to understand – how can a line be perpendicular to a curved surface?… Continue reading 25.8 The sphere: tangent plane, surface area and volume
Thinking about Science with David Hukins 