A light emitting diode (LED) emits light only when it isI. unbiasedII. reverse biasedIII. forward biased
Correct answer: A. II only.
- A. II only.
- B. III only.
- C. I and II.
- D. I and III.
Explanation
The correct answer is Option A: II only. An LED emits light only when it is reverse biased. When an LED is forward biased or unbiased, it does not emit light. Therefore, options B, C, and D are incorrect as they do not accurately reflect the biasing conditions required for an LED to emit light.
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About PN Junction
A PN junction forms when p type and n type semiconductor regions meet, creating a depletion layer and a potential barrier. The topic covers forward and reverse bias, diode current voltage characteristics, breakdown and rectification, while distinguishing an ordinary junction diode from a transistor formed from multiple junctions.
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