In reverse bias, the current through an ideal diode is
- A. large
- B. the same as in forward bias
- C. almost zero, apart from a small leakage current
- D. infinite
Explanation
The widened depletion region blocks the majority carriers, leaving only the thermally generated minority carriers to cross, which gives a leakage current of the order of microamperes. If the reverse voltage rises far enough the junction breaks down and conducts heavily, which is destructive for an ordinary diode but is the intended operating mode of a Zener diode. Ideal diode analysis simply treats the reverse current as zero.