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Question 231

What causes a light-emitting diode (LED) to emit light?

  1. Forward currentCorrect answer
  2. Reverse current
  3. Capacitively-coupled RF signal
  4. Inductively-coupled RF signal

Explanation

An LED emits light when it is forward biased and forward current passes through the junction, releasing energy as photons. Under reverse bias it does not conduct at all, so no light is produced.

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Question 231: What causes a light-emitting diode (LED) to emit light? · FCC Technician Class (Element 2) · Questena