PN Junction Diode MCQs with Applications
PN Junction Diode MCQs with Applications
Class: CBSE Class 12 | Subject: Physics
Section 9: Electronic Devices
Topic: PN Junction Diode & Applications
Based on CBSE Board Examination Pattern
Section 9: Electronic Devices
Topic: PN Junction Diode & Applications
Based on CBSE Board Examination Pattern
Instructions: These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 12 Board Examination preparation.
1. A PN junction is formed by joining:
Answer: B
A PN junction forms when p‑type and n‑type semiconductor regions are fabricated in a single crystal.
A PN junction forms when p‑type and n‑type semiconductor regions are fabricated in a single crystal.
2. Depletion region contains:
Answer: C
Electrons and holes recombine leaving fixed charged ions.
Electrons and holes recombine leaving fixed charged ions.
3. Barrier potential in silicon diode ≈
Answer: B
Silicon PN junction typically has 0.7 V barrier.
Silicon PN junction typically has 0.7 V barrier.
4. Forward bias means:
Answer: B
External supply reduces barrier allowing current.
External supply reduces barrier allowing current.
5. Reverse bias current is due to:
Answer: B
Minority carriers produce small leakage current.
Minority carriers produce small leakage current.
6. PN diode acts as:
Answer: B
Allows current in one direction.
Allows current in one direction.
7. Ideal diode resistance in forward bias:
Answer: A
Ideal diode offers no resistance.
Ideal diode offers no resistance.
8. Reverse breakdown types:
Answer: C
Two breakdown mechanisms.
Two breakdown mechanisms.
9. Zener diode used for:
Answer: C
Maintains constant output voltage.
Maintains constant output voltage.
10. LED works in:
Answer: A
Light emitted during recombination.
Light emitted during recombination.
11. Photodiode operates in:
Answer: B
Detects light via reverse current.
Detects light via reverse current.
12. Rectifier converts:
Answer: A
Basic diode application.
Basic diode application.
13. Peak inverse voltage means:
Answer: B
Maximum reverse voltage diode withstands.
Maximum reverse voltage diode withstands.
14. Germanium barrier potential:
Answer: A
Lower than silicon.
Lower than silicon.
15. Full wave rectifier uses:
Answer: B
Centre‑tap (2) or bridge (4).
Centre‑tap (2) or bridge (4).
16. Depletion width increases in:
Answer: B
Barrier widens opposing current.
Barrier widens opposing current.
17. Diode symbol arrow shows:
Answer: C
Represents conventional current direction.
Represents conventional current direction.
18. Junction capacitance exists in:
Answer: B
Acts as parallel plate capacitor.
Acts as parallel plate capacitor.
19. Solar cell is:
Answer: A
Converts light to electricity.
Converts light to electricity.
20. Diode current equation is:
Answer: B
Follows exponential I‑V characteristics.
Follows exponential I‑V characteristics.
