Electromagnetic Waves

Revision sheet excerpt

Course Outline

  1. Maxwell’s Electromagnetic Unification
  2. Displacement Current
  3. Ampere–Maxwell Law
  4. Sources of Electromagnetic Waves
  5. Structure of Electromagnetic Waves
  6. Wave Speed and Energy
  7. Electromagnetic Spectrum
  8. Applications of Spectrum Regions

1. Maxwell’s Electromagnetic Unification

★ Must-know

  • James Clerk Maxwell (1831–1879) showed that a time-varying electric field generates a magnetic field, completing the symmetry with Faraday’s result that a time-varying magnetic field generates an electric field.

  • Maxwell’s equations, together with the Lorentz force formula, express the basic laws of electromagnetism and predict electromagnetic waves as coupled time-varying electric and magnetic fields propagating through space. — James Clerk Maxwell

  • The predicted speed of electromagnetic waves was close to 3×108 ms13 \times 10^8\ \mathrm{m\,s^{-1}}, the measured speed of light, leading to the conclusion that light is an electromagnetic wave. — James Clerk Maxwell

Further detail

  • Hertz experimentally demonstrated electromagnetic waves in 1885, and their technological use by Marconi and others led to modern communication.

Memory Hook

Read the full sheet →

Quiz preview

1. What electromagnetic relationship did Maxwell add to complement Faraday’s law?

2. What do Maxwell’s equations together with the Lorentz force formula provide?

3. Why did Maxwell conclude that light is an electromagnetic wave?

Take the quiz (23 questions) →

Flashcards preview

Who showed that a time-varying electric field generates a magnetic field?

James Clerk Maxwell.

What do Maxwell’s equations and the Lorentz force formula express?

The basic laws of electromagnetism.

What do Maxwell’s equations predict about electromagnetic waves?

They are coupled time-varying electric and magnetic fields propagating through space.

What speed did Maxwell predict for electromagnetic waves?

Close to 3 × 10^8 meters per second.

What conclusion was drawn from the predicted speed of electromagnetic waves?

That light is an electromagnetic wave.

Who experimentally demonstrated electromagnetic waves in 1885?

Heinrich Hertz.

See all 55 flashcards →

Frequently asked questions

What does the revision sheet on Electromagnetic Waves cover?

The revision sheet covers the essential concepts of Electromagnetic Waves. It is organized by topic to facilitate learning and memorization, with key definitions, explanations and summaries.

Read the full sheet →

How many questions are in the Electromagnetic Waves quiz?

The quiz contains 23 multiple-choice questions with detailed corrections and explanations for each answer. Ideal for testing your knowledge and identifying gaps.

Take the quiz (23 questions) →

How to study Electromagnetic Waves with flashcards?

Revizly offers 55 interactive flashcards on Electromagnetic Waves. Each card presents a question on the front and the answer on the back, enabling active and effective revision based on spaced repetition.

See all 55 flashcards →

Similar courses

Create your own sheets from your courses

Import your PDF or paste your course, AI generates sheets, quizzes and flashcards in 30 seconds.