Name of the College : Noorul Islam College of Engineering
University : Anna University
Degree : B.E
Department : Mechanical Engineering
Subject Code/Name : EC 1264 – Electronics & Microprocessor
Year : 2nd
Semester : 3rd
Document Type : Question Bank
Website : niceindia.com
Download Model/Sample Question Paper :https://www.pdfquestion.in/uploads/niceindia.com/3018-EC_1264_Electronic_and_microprocessor.pdf
NICE Electronics & Microprocessor Question Paper
Unit I Semiconductor Theory :
1. What are valence electrons? :
Electron in the outer most shell of an atom is called valence electron.
Related : Noorul Islam College of Engineering ME1402 Computer Integrated Manufacturing B.E Question Bank : www.pdfquestion.in/3019.html
2. What is forbidden energy gap? :
The space between the valence and conduction band is said to be forbidden energy gap.
3. What are conductors? : Give examples?:
Conductors are materials in which the valence and conduction band overlap each other so there is a swift movement of electrons which leads to conduction. Ex. Copper, silver.
4. What are insulators? : Give examples?:
Insulators are materials in which the valence and conduction band are far away from each other. So no movement of free electrons and thus no conduction. Ex glass, plastic.
5. What are Semiconductors? : Give examples?:
The materials whose electrical property lies between those of conductors and insulators are known as Semiconductors. Ex germanium, silicon.
6. What are the types of Semiconductor? :
1. Intrinsic semiconductor 2. Extrinsic semiconductor.
7. What is Intrinsic Semiconductor? :
Pure form of semiconductors are said to be intrinsic semiconductor. Ex germanium, silicon.
8. What is Extrinsic Semiconductor? :
If certain amount of impurity atom is added to intrinsic semiconductor the resulting semiconductor is Extrinsic or impure Semiconductor.
9. What are the types of Extrinsic Semiconductor? :
1. P-type Semiconductor 2. N- Type Semiconductor.
10. What is P-type Semiconductor? :
The Semiconductor which are obtained by introducing pentavalent impurity atom (phosphorous, antimony) are known as P-type Semiconductor.
11. What is N-type Semiconductor? :
The Semiconductor which are obtained by introducing trivalent impurity atom (gallium, indium) are known as N-type Semiconductor.
12. What is doping? :
Process of adding impurity to an semiconductor atom is doping. The impurity is
called dopant.
13. Which is majority and minority carrier in N-type Semiconductor? :
Majority carrier : electrons and minority carrier: holes.
14. Which is majority and minority carrier in P-type Semiconductor? :
Majority carrier : holes and minority carrier: electrons.
15. What is depletion region in PN junction? :
The diffusion of holes and electrons will result in difference in concentration across the junction which in turn results in the movement of the mobile charge carriers to the junction thus resulting in a region called depletion region.
16. What is barrier voltage? :
Because of the oppositely charged ions present on both sides of PN junction an electric potential is established across the junction even without any external voltage source which is termed as barrier potential.
17. What is meant by biasing a PN junction? :
Connecting a PN junction to an external voltage source is biasing a PN junction.
18. What are the types of biasing a PN junction? :
1. Forward bias 2. Reverse bias.
19. What is forward bias and reverse bias in a PN junction? :
When positive of the supply is connected to P type and negative to N type then it is forward bias. When positive of the supply is connected to N type and negative to P type then it is reverse bias.
20. What is Reverse saturation current? :
The current due to the minority carriers in reverse bias is said to be reverse saturation current.