Enroll Course: https://www.coursera.org/learn/dianci-2
For anyone looking to solidify their understanding of electromagnetism, especially those who have completed an introductory course, Coursera’s “Electromagnetism II – Steady Magnetic Fields and Time-Varying Electromagnetic Fields” (电磁学下——恒磁场与时变电磁场) is an exceptional resource. This course, building directly upon foundational concepts, delves into the more complex and fascinating aspects of magnetic fields, electromagnetic induction, AC circuits, and the fundamental nature of electromagnetic waves.
The course is meticulously structured into six modules, each focusing on a specific area of study. This modular approach allows for a systematic progression through the material, ensuring that learners grasp each concept before moving on. The syllabus covers:
* **Module 1: Basic Laws of Steady Magnetic Fields:** This section revisits the historical development of magnetic field research, introduces the definition of magnetic flux density, and explains Ampere’s Circuital Law and Gauss’s Law for Magnetism. It emphasizes the practical application of methods like the micro-element method and symmetry principles for calculating magnetic fields, drawing parallels with electric field calculations while highlighting key differences.
* **Module 2: Magnetic Force:** Here, the course focuses on Ampere’s force and the Lorentz force, integrating high school knowledge into a university-level framework. It explores the motion of charged particles in electromagnetic fields, with a particular emphasis on the Lorentz force and the Hall effect, touching upon its significant impact on physics and technology.
* **Module 3: Magnetic Materials:** This module introduces magnetic materials, drawing analogies with electric polarization. It explains magnetization from a molecular current perspective, discusses magnetic field laws in the presence of materials (including the classification of diamagnetic, paramagnetic, and ferromagnetic materials), and covers boundary conditions.
* **Module 4: Electromagnetic Induction:** This section revisits electromagnetic induction, building upon prior knowledge. It delves into the establishment of Faraday’s Law, the distinction between motional and induced electromotive force (EMF), and introduces eddy currents and vortex electric fields. The concepts of self-inductance and mutual inductance are explored, along with magnetic field energy.
* **Module 5: Alternating Current and AC Circuits:** This module tackles the intricacies of AC circuits, requiring a solid grasp of mathematical concepts like complex numbers and calculus. It covers the characteristics of simple harmonic AC, impedance, phase relationships, and methods for solving AC circuits, including phasor diagrams and complex number analysis. Resonance circuits and AC power are also key topics.
* **Module 6: Electromagnetic Fields and Electromagnetic Waves:** The concluding module provides an overview of Maxwell’s electromagnetic theory, introduces the concept of displacement current and Maxwell’s equations, and discusses the properties of electromagnetic waves in free space. It also touches upon electromagnetic energy and the Poynting vector.
What makes this course particularly effective is its pedagogical approach. Each module is broken down into several lessons, followed by self-assessment quizzes. This allows learners to pace themselves, revisit unclear concepts, and reinforce their understanding. The instructors clearly aim to make a theoretically dense subject accessible, providing historical context and practical examples to illustrate complex principles.
While the course is challenging, as expected for a university-level physics subject, the structured format and clear explanations make it manageable. The instructors’ advice to persevere, especially with the problem sets, is crucial for success. The course is highly recommended for undergraduate physics students, aspiring electrical engineers, and anyone seeking a rigorous yet comprehensive understanding of classical electromagnetism.
Enroll Course: https://www.coursera.org/learn/dianci-2