Electromagnetic waves are produced by:
Correct answer: A. Oscillating electric charges and their fields
- A. Oscillating electric charges and their fields
- B. Neutral particles in motion
- C. Stationary electric charges
- D. Heat transfer
- E. None of the above
Explanation
Electromagnetic waves are the combination of electric and magnetic field waves produced by moving charges.The creation of all electromagnetic waves begins with a charged particle. This charged particle creates an electric field (which can exert a force on other nearby charged particles). When it accelerates as part of an oscillatory motion, the charged particle creates ripples, or oscillations, in its electric field, and also produces a magnetic field (as predicted by Maxwell's equation).
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About Alternating Current
Alternating current varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
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