Practice question · Multiple choice
Faraday's law shows that a changing magnetic field drives an electric field, whilst Maxwell's addition shows that a changing electric field drives a magnetic field. What fundamental consequence follows from this mutual coupling in completely empty space?
Hints
- What happens when you take the curl of Faraday's law and substitute Maxwell's modified Ampère's law in source-free space?
- Does the generation of one field by the variation of another require any matter or physical carriers to sustain itself?
Show the answer
C. Fields propagate as self-sustaining waves without charges
Why
Mutual induction allows fields to regenerate one another through empty space rather than decaying, creating propagating radiation. Treating displacement current as real charge transport or assuming fields require matter to exist overlooks how Maxwell unifies optics with electromagnetism.
Practise Maxwell’s Equations and Electromagnetic Waves
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More questions on Maxwell’s Equations and Electromagnetic Waves
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