Semiconductor Electronics MCQs Class 12 Physics
Semiconductor Electronics MCQs Class 12 Physics
Class: CBSE Class 12 | Subject: Physics
Section 9: Electronic Devices
Topic: Semiconductor Electronics
Based on CBSE Board Examination Pattern
Section 9: Electronic Devices
Topic: Semiconductor Electronics
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 semiconductor has conductivity between:
Answer: A
Semiconductors have moderate conductivity between conductors and insulators.
Semiconductors have moderate conductivity between conductors and insulators.
2. Example of intrinsic semiconductor:
Answer: C
Pure Si and Ge are intrinsic semiconductors.
Pure Si and Ge are intrinsic semiconductors.
3. Doping means:
Answer: B
Impurities are added to increase conductivity.
Impurities are added to increase conductivity.
4. Pentavalent impurity produces:
Answer: B
Pentavalent atoms donate electrons → n‑type.
Pentavalent atoms donate electrons → n‑type.
5. Majority carriers in p‑type:
Answer: B
Holes dominate conduction in p‑type.
Holes dominate conduction in p‑type.
6. PN junction forms by:
Answer: B
p & n regions create junction.
p & n regions create junction.
7. Depletion region contains:
Answer: B
Charge carriers recombine leaving ions.
Charge carriers recombine leaving ions.
8. Forward bias reduces:
Answer: B
Barrier decreases enabling current.
Barrier decreases enabling current.
9. Reverse bias current is:
Answer: C
Only minority carriers conduct.
Only minority carriers conduct.
10. Zener diode works in:
Answer: B
Used as voltage regulator.
Used as voltage regulator.
11. LED emits light due to:
Answer: B
Electron‑hole recombination releases photons.
Electron‑hole recombination releases photons.
12. Photodiode converts:
Answer: A
Works as light sensor.
Works as light sensor.
13. Transistor has terminals:
Answer: B
Emitter, Base, Collector.
Emitter, Base, Collector.
14. Transistor used as:
Answer: D
Multiple electronic applications.
Multiple electronic applications.
15. Logic gate performing NOT:
Answer: C
Inverts input signal.
Inverts input signal.
16. Silicon valency:
Answer: C
Tetravalent semiconductor.
Tetravalent semiconductor.
17. n‑type majority carriers:
Answer: B
Electrons dominate conduction.
Electrons dominate conduction.
18. Rectifier converts:
Answer: B
Diodes rectify AC supply.
Diodes rectify AC supply.
19. Barrier potential in Si ≈
Answer: B
Typical silicon junction value.
Typical silicon junction value.
20. NAND gate is combination of:
Answer: A
NOT operation on AND output.
NOT operation on AND output.