Download EC6201 QB

EC6201-ELECTRONIC DEVICES
UNIT-1
PART_A
1.Define mass action law
(May/June2014)
2.What is the principal operation of PN Junction diode in reverse bias
condition?
(May/June 2014)
3.State the effect of temperature of PN junction diode.
(Nov/dec2012)
4.What is diffusion capacitance?
(Nov/dec2012)
5.Give the expression for transition capacitance and diffusion capacitance of
a PN diode.
(June 2010)
6. Define avalanche breakdown?
(Jun 2010)
7.Distinguish between intrinsic and extrinsic semiconductors.
(May/June 2013)
8. Mention the two types of junction capacitances
(May/June 2013)
9. Define transition capacitance
(May/June 2009)
10.What are semiconductors?
11.Define drift current?
12.Give the expression for drift current density
13.Define the term diffusion current?
14.Give the expression for diffusion current density
15.Differentiate between drift and diffusion currents.
16.What is depletion region in PN junction?
17.What is barrier potential?
18.What is Reverse saturation current?
19.What is the total current at the junction of pn junction diode?
20.Give the diode current equation?
21.what is recovery time? Give its types.
22.Define storage time.
23.Define transition time.
24.Define PIV.
25.Draw V-I characteristics of pn diode
26. Write the application of pn diode
UNIT-2
PART-A
1. what is the need for biasing in the transistor?
(May/June2014)
2. Draw the h-parameter model for CE transistor
(May/June2014)
3. What is “Early effect” in CB configuration and give its consequences?
(Jun 2010)
4. Give the biasing arrangement for an NPN transistor to operate in active
region.
(May/June 2013)
5. What is large signal current gain?
(May/June 2009)
6. Why an ordinary transistor is called bipolar?
7. Collector region of transistor is larger than emitter. Why?
8. Why is BJT is called current controlled device?
9. Define Early Effect.
10. Draw the characteristics of CE configuration.
11. Among CE, CB, CC which one is most popular. Why?
12. Compare CE, CB, CC.
13. Why h parameter model is important for BJT
14. Define current amplification factor
15. What do you meant by multi emitter transistor?
16.In a CR connection, the value of IE is 6.28 mA and the collector current
Ic is 6.20 mA. Determine d.c. current gain.
17. The transistor has IE = 10 mA and α = 0.98. Find the value of base and
collector currents.
18. If a transistor has a α of 0.97 find the value of β. If β=200, find the value
of α
19. Give some applications of BJT.
UNIT-3
PART-A
1.In which region JFET act as a resistor and why?
(May/June2014)
2.Differentiate between JFET and BJT
(May/June2014)
3.When a FET act as a voltage variable resistor?
(Nov/dec2012)
4. Distinguish clearly the difference between N with P channel FETs
(Jun 2010)
5. Write the equation for drain current of JFET.
(May/June 2013)
6. compare any four salient feature of BJT with JFET
(May/June 2009)
7. Why it is called field effect transistor?
8. Why FET is called voltage controlled device.
9. Define the term threshold voltage.
10. What is channel length modulation?
11. Compare JFET with BJT.
12. Draw the transfer characteristics curve for JFET.
13. Differentiate between N and P channel FETs
14. Write some applications for JFET.
15. Compare MOSFET with JFET.
16. Compare N channel MOSFET with P channel MOSFET.
17. Differentiate between current voltage relationships of the N channel and
P channel MOSFET
18.Draw the V-I characteristics curve of MOSFET.
UNIT-4
PART-A
1. Draw the energy band diagram of metal and semiconductor before and
after conduction is made.
(May/June2014)
2. List out the application of tunnel diode.
(May/June2014)
3. What is tunneling phenomenon?
(Nov/dec2012)
4. Give some applications of tunnel diode
(Jun 2010)
5. Draw the equivalent circuit of tunnel diode
(May/June 2009)
6. What is a metal semiconductor contact?
7. Define contact potential in metal semiconductor contact.
8. Give the symbol and structure of schottky diode.
9. Give the applications of schottky diode.
10. Compare between schottky diode and conventional diode.
11. Why zener diode is often preferred than PN diode.
12. Draw the V-I characteristics curve for zener diode.
13. What is zener breakdown?
14. What is avalanche break down?
15. What is tunneling phenomenon?
16. Give the application of tunnel diode.
17. Give the advantages and disadvantages of tunnel diode
18. Draw equivalent circuit of tunnel diode
19. What is varactor diode?
UNIT-5
PART-A
1. Draw the basic structure of TRIAC and its symbol
2. Write down the significance of opto coupler.
3. Name any two applications of photoconductive cell.
4. What is meant by photovoltaic cell?
5. Draw the two transistor equivalent circuit of SCR
6. Compare LED and LCD
7. What is intrinsic stand-off ratio?
8. Give the V-I characteristics of UJT.
9. Mention the applications of UJT.
(May/June2014)
(May/June2014)
(Nov/Dec2012)
(Jun 2010)
(May/June 2013)
(May/June 2013)
(May/June 2013)
10. What is a TRIAC? Give the symbol and structure of TRIAC.
11. Draw the V-I characteristics for TRIAC.
12. Give the application of TRIAC.
13. What is a DIAC? Give the basic construction and symbol of DIAC.
14. Draw the V-I curve for DIAC
15. Give some applications of DIAC.
16. Why SCR cannot be used as a bidirectional switch.
17.How turning on of SCR is done?
18. How turning off of SCR is done?
19.Define holding current in a SCR.
20. List the advantages of SCR.
21.List the application of SCR.
22. Compare SCR with TRIAC
23.Differentiate BJT and UJT.
24.State the principle of operation of an LED
25.Give the advantages of LED
26.State some disadvantages of LED
27.List the applications of LED
UNIT-1
PART-B
1.Explain the theory of PN junction diode and derive its diode current
equation.
(16) (May/June 2014)
2.Explain and derive current component and switching characteristics of
diode.
(16)(May/June 2014)
3.Derive the PN diode current equation from the quantitative theory of diode
currents
(16) (Nov/Dec 2012)
4.Explain briefly the following
a) Avalanche breakdown
(4) (Nov/Dec 2012 )
b) Zener breakdown
(4) (Nov/Dec 2012)
5. Derive the PN junction diode current equation
(8) (Jun 2010)
6. Explain how the depletion region at a PN junction is formed and explain
with relevant sketches for charge density, electric field intensity and
potential energy barriers at the junction
(8) (Jun 2010)
7. Explain the theory of PN junction diode along with its V-I characteristics
(8) (May/June 2013)
8. Discuss the effect of temperature upon the characteristics of PN junction
diode
(8) (May/June 2013)
9. Distinguish between avalanche breakdown and zener breakdown
(8) (May/June 2013)
10. Derive the PN diode current equation from the quantitative theory of
diode current
(16) (May/June 2009)
11. Define and derive the drift and diffusion current
(8) (May/June 2009)
UNIT-2
PART-B
1.Explain the characteristics of BJT in CC,CE,CB configuration and
compare the performance of a transistor in different configurations (16)
(May/June 2014)
2.Draw a voltage divider bias circuit and derive an expression for its stability
factor
(16)(May/June 2014)
3.Draw the circuit for CE configuration of an NPN transistor and explain in
brief is input and output characteristics.
(10) (Nov/Dec 2012)
4.Compare the performance of CE,CB, and CC configurations (6)
(Nov/Dec2012)
5.Explain the input and output characteristics of a CE configuration with a
neat sketch
(16) (Jun 2010)
6.Draw and explain the characteristics of PNP transistor in CB configuration
(8) (May/June 2013)
7.compare CB,CE and CC transistor configurations
(8) (May/June 2013)
8. Explain the CE configuration of BJT in detail with required diagrams (10)
(May/June 2009)
9. Define and compare α,β & γ
(6) (May/June 2009)
UNIT-3
PART-B
1. Discuss about FINFET and Dual Gate MOSFET
(8)
(May/June 2014)
2. Explain the four distinct regions of the output characteristics of the JFET
(8) (May/June 2014)
3. With the help of suitable diagram explain the working of different type of
MOSFET
(10) (May/June 2014)
4. Briefly describe some application of JFET
(6) (May/June 2014)
5. Sketch and explain the construction of N-channel JFET. Give also its
symbol
(4) (Nov/Dec2012)
6. Explain the operation of N-channel JFET. Sketch and explain the drain
characteristics.
(8) (Nov/Dec2012)
7. Define the following parameters of JFET
(4) (Nov/Dec 2012)
(a)Trans conductance
(b) Drain resistance
(c) Amplification factor
(d) Power dissipation.
8. What is MOSFET? Explain the construction and working principle of
enhancement mode and depletion mode MOSFET with a neat diagram (16)
(Jun 2010)
9. Describe the construction, operation and characteristics of N-channel
JFET
(8) (May/June 2013)
10. Draw the structure of N-channel depletion type MOSFET and explain its
operation and characteristics
(8) (May/June 2013)
UNIT-4
PART-B
1.Draw the VI characteristics of zener diode and explain its operation
(8)(May/June 2014)
2. Write short notes on schottky diode
(8) (May/June 2014)
3. Explain the principal behind the varactor diode and list out its application
(8) (May/June 2014)
4. Give the details about the Laser diode
(8) (May/June 2014)
5. What is tunneling? Describe the V-I characteristics and concepts of tunnel
diode with application.
(16) (Jun 2010)
6. With energy band diagram, explain the theory and characteristics of tunnel
diode
(10) (May/June 2013)
7. Write notes on varactor diode
(6) (May/June 2013)
UNIT-5
PART-B
1. Explain the operation, characteristics and application of SCR (16)
(May/June 2014)
2. Write short notes on: (i) solar cell (8) (ii) CCD (8)
(May/June 2014)
3. Explain the construction, operation and characteristics of UJT (8)
(Nov/Dec 2012)
4. Sketch the symbol of DIAC and explain its operation and characteristics
(8) (Nov/Dec2012)
5. Explain the negative resistance characteristics of UJT with neat sketch (16)
(Jun 2010)
6. Describe the construction, operation and characteristics of UJT (8)
(May/June 2013)
7. Discuss the operation and characteristics of photodiode. Mention the
application of photodiodes and phototransistors.
(8) (May/June 2013)
8. Explain the construction and operation of LCD
(16) (May/June 2009)
9. Draw and explain the two transistor equivalent model of SCR (10)
(May/June 2009)
10. Draw and explain the V-I characteristic of TRIAC (6) (May/June 2009)