Last Minute Lecture

Electromagnetic Waves – Principles & Applications Explained | Chapter 32 of University Physics Chapter 32 unifies electricity and magnetism into the self-sustaining phenomenon of electromagnetic waves. We’ll explore how Maxwell’s equations predict wave propagation at the speed of light, the transverse nature of E and B fields, energy and momentum transport, standing wave formation, and real-world applications from radio to lasers. Watch the full video summary here for animated demonstrations of EM wave behavior. Maxwell’s Equations & Wave Generation Maxwell’s extension of Faraday’s and Ampère’s laws shows that time-varying E fields induce B fields and vice versa, forming a self-propagating wave. The wave speed in vacuum is: c = 1/√(ε₀ μ₀) ≈ 3.00×10⁸ m/s , matching the measured speed of light and confirming light as an electromagnetic wave. Plane Waves & Transverse Nature Electromagnetic waves are transverse: E and B oscillate perpendicular to each other and t...

Electromagnetic Induction – Faraday’s Law, Generators & Superconductivity Explained | Chapter 29 of University Physics Chapter 29 unveils how changing magnetic fields produce electric currents and voltages—an effect central to generators, transformers, and countless modern devices. You’ll learn Faraday’s and Lenz’s laws, explore motional emf, nonconservative induced fields, eddy currents, Maxwell’s unification of electricity and magnetism, and the remarkable phenomenon of superconductivity. Watch the full video summary here for detailed examples and visual demonstrations. Magnetic Flux & Faraday’s Law Magnetic flux through a loop is: Φ B = B · A · cos φ , where B is the field, A the loop area, and φ the angle between them. Faraday’s Law states that a changing flux induces an emf: ℰ = – dΦ B /dt . For N loops: ℰ = – N dΦ B /dt . The negative sign embodies Lenz’s Law, ensuring the induced emf opposes the flux change. Lenz’s Law Lenz’s Law dictates that the ...