Question
What causes a light-emitting diode (LED) to emit light?
Answer Options
- A) Forward current
- B) Reverse current
- C) Capacitively-coupled RF signal
- D) Inductively-coupled RF signal
Correct Answer: A
Explanation
An LED is a special type of semiconductor diode used as a visual indicator (T6D07). Like all diodes, it allows current to flow easily in only one direction. When a sufficient forward current flows through the LED (from anode to cathode), the internal recombination of electrons and holes releases energy in the form of light.
If the current attempts to flow in the reverse direction, the LED acts like a blocked diode and will not light up. Too much reverse current can permanently damage the component.
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