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EM wave properties
Intermediate
Transverse waves with E and B perpendicular.
c = 1/√(μ₀ε₀)EM waves are transverse, E ⊥ B ⊥ direction, in phase, travelling at c = 1/√(μ₀ε₀) in vacuum, with E = cB. They carry energy and momentum and need no medium.
All colours of light travel at the same speed in vacuum.
They are not matter waves.
In more detail
Electromagnetic waves are transverse, with electric and magnetic fields perpendicular to each other and to the direction of travel. They travel at the speed of light in vacuum and carry energy and momentum.
Real-world uses
- Radio, microwave, infrared, visible and X-ray radiation are all electromagnetic waves.
- Solar panels convert electromagnetic energy into electricity.
- Engineers designing antennas and optical systems rely on the transverse nature of electromagnetic waves.
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Frequently asked questions
Are electromagnetic waves transverse?
Yes, both the electric and magnetic fields are perpendicular to the direction of propagation.
Do they need a medium?
No. They propagate through vacuum.
What is the speed of an electromagnetic wave in vacuum?
About 3 times 10 to the eighth metres per second, the speed of light.
Related topics in AC Circuits & EM Waves
Rectification and smoothing · Displacement current · EM wave generation · Speed of light · EM wave equation · Relation between E and B