MCQs on PN junction diode
Q: In a PN junction with no external voltage, the electric field between acceptor and donor ion is called a
- Peak
- Barrier
- Threshold
- Path
Answer: (2) Barrier
Q: In a PN junction the potential barrier is due to the charges on either side of the junction, these charges are
- Majority carriers
- Minority carriers
- Both (a) and (b)
- Fixed donor and accepter ions
Answer: (4) Fixed donor and accepter ions
Q: The capacitance of a reverse-biased PN junction
- Increases as reverse bias is increased
- Decreases as reverse bias is increased
- Increases as reverse bias is decreased
- Is significantly low
Answer: (3) Increases as reverse bias is decreased
Q: For a PN junction diode, the current in reverse bias maybe
- Few milliamperes
- Between 0.2 A and 15 A
- Few amperes
- Few micro or nano amperes
Answer: (4) Few micro or nano amperes
Q: When PN junction is in forward bias, by increasing the battery voltage
- Circuit resistance increases
- Current through P_N junction increases
- Current through P_N junction decreases
- None of the above
Answer: (2) Current through P_N junction increases
Q: When a PN junction is reverse biased
- Holes and electrons tend to concentrate towards the junction
- The barrier tends to break down
- Holes and electrons tend to move away from the junction
- None of these
Answer: (3) Holes and electrons tend to move away from the junction
Q: A PN junction
- Has low resistance in forward as well as reverse directions
- Has high resistance in forward as well as reverse directions
- Conductors in the forward direction only
- Conducts in the reverse direction only
Answer: (3) Conductors in the forward direction only
Q: A PN junction is said to be forward-biased when
- The positive terminal of the battery is connected to P-side and the negative side to the N-side
- Junction is earthed
- N-side is connected directly to the p-side
- The positive terminal of the battery is connected to N-side and the negative side to the P-side.
Answer: (1) The positive terminal of the battery is connected to P-side and the negative side to the N-side
Q: PN junction failure below 5 V is caused primarily by
- Avalanche breakdown
- Zener breakdown
- Either (a) or (b)
- None of the above
Answer: (2) Zener breakdown
Q: In a reverse-biased PN junction, the current through the junction increases abruptly at
- 0.5 V
- 1.1 V
- 0.72 V
- Breakdown voltage
Answer: (4) Breakdown voltage