Download Visvesvaraya Technological University (VTU) BE ( Bachelor of Engineering) ECE (Electronic engineering) 2018 Scheme 2020 January Previous Question Paper 3rd Sem 18EC33 Electronic Devices
USN
18EC33
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Third Semester B.E. Degree Examination, Dec:20
,
19-1Jan.2020
Electronic Devices
Time: 3 hrs. Max. Marks: 100
Note: ,
,
Inswer FIFE full questions, choosing ONE full question from each module.
Module-I
a_ What are the types of Bonding forceses in solids? Explain. (06 Marks)
b. Explain the classification of material based on conductivity and energy band diagram.
(08 Marks)
Find the conductivity of the intrinsic germanium at 300 K. If a donar type impurity is added
to the extent of I atom/10
7
germanium atom assume =3800, vi
p
=1800 , n
;
= 2.5 x10
3
,
Q = 1.602 x10
-19
(06 Marks)
OR
2 a. What are Direct and Indirect band gap semiconductor? Explain with examples. (08 Marks)
b. Explain the concentration of electron-hole pair in Intrinsic semiconductor with energy band
diagram. (06 Marks)
c. Calculate the Intrinsic carrier concentration in Silicon at room temperature T = 300 K ,
where B is the material dependent parameter 5.4 x10
31
and F:, as the bandgap energy
1.12 eV, where K is the Boltzrnan constant = 8.62 X10
-5
eV/K. (06 Marks)
Module-2
3 a. With energy band diagram, explain the doping level in extrinsic semiconductor at 0 K and at
50 K. (09 Marks)
b. What is the magnitude of HALL voltage in a N-Type germanium bar having an majority
carrier concentration N
I
, =10'
7
cm
3
. Assume B = 0.2 Wb/m
2
, d = 2 mm, E = 10 V/cm.
(05 Marks)
c.
Explain the effect of temperature on semiconductor. (06 Marks)
OR
4 a. Explain the qualitative description of current flow at P-N junction under equilibrium and
biased condition. (08 Marks)
b Explain zener breakdown and avalanche breakdown under reverse biased P-N junction.
(06 Marks)
c.
Discuss the piece-wise linear approximations of junction diode under ideal condition.
(06 Marks)
Module-3
5 a. Explain the optical generation of carrier in a P-N junction_ (08 Marks)
b. Discuss the configuration of a solar cell in enlarged view of the planar junction. (06 Marks)
c. What is injectiOn-electroluminiscence and what are its applications? (06 Marks)
1 of 2
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USN
18EC33
u
e
`
ti
ti)
1Z
-
2,
l
g
ri)
o
tf)
?- a
?
E
5
"
)
ra
C)
z
Third Semester B.E. Degree Examination, Dec:20
,
19-1Jan.2020
Electronic Devices
Time: 3 hrs. Max. Marks: 100
Note: ,
,
Inswer FIFE full questions, choosing ONE full question from each module.
Module-I
a_ What are the types of Bonding forceses in solids? Explain. (06 Marks)
b. Explain the classification of material based on conductivity and energy band diagram.
(08 Marks)
Find the conductivity of the intrinsic germanium at 300 K. If a donar type impurity is added
to the extent of I atom/10
7
germanium atom assume =3800, vi
p
=1800 , n
;
= 2.5 x10
3
,
Q = 1.602 x10
-19
(06 Marks)
OR
2 a. What are Direct and Indirect band gap semiconductor? Explain with examples. (08 Marks)
b. Explain the concentration of electron-hole pair in Intrinsic semiconductor with energy band
diagram. (06 Marks)
c. Calculate the Intrinsic carrier concentration in Silicon at room temperature T = 300 K ,
where B is the material dependent parameter 5.4 x10
31
and F:, as the bandgap energy
1.12 eV, where K is the Boltzrnan constant = 8.62 X10
-5
eV/K. (06 Marks)
Module-2
3 a. With energy band diagram, explain the doping level in extrinsic semiconductor at 0 K and at
50 K. (09 Marks)
b. What is the magnitude of HALL voltage in a N-Type germanium bar having an majority
carrier concentration N
I
, =10'
7
cm
3
. Assume B = 0.2 Wb/m
2
, d = 2 mm, E = 10 V/cm.
(05 Marks)
c.
Explain the effect of temperature on semiconductor. (06 Marks)
OR
4 a. Explain the qualitative description of current flow at P-N junction under equilibrium and
biased condition. (08 Marks)
b Explain zener breakdown and avalanche breakdown under reverse biased P-N junction.
(06 Marks)
c.
Discuss the piece-wise linear approximations of junction diode under ideal condition.
(06 Marks)
Module-3
5 a. Explain the optical generation of carrier in a P-N junction_ (08 Marks)
b. Discuss the configuration of a solar cell in enlarged view of the planar junction. (06 Marks)
c. What is injectiOn-electroluminiscence and what are its applications? (06 Marks)
1 of 2
18E
(08 Marks)
(06 Marks)
6 a.
b.
OR
Explain 1-V characteristics of n-p junction as a function
,
:of emitter current.
Discuss switching operation in common-emitter transistor.
c. Figure Q6 (c) shows the common emitter amplifier circuit. Calculate 1B and lc assume
Tp = 1 0 pts , = 0.1 pi.s (06 Marks)
5
V
Fig. Qb (c)
Module-4
7 a. DraW and explain the 1-V characteristics of n-channel PNJFET for different biasing
voltages. (07 Marks)
h. Draw and explain the small signal equivalent circuit of n-channel PNJFET. (07 Marks)
c. Explain the MOS structure with the aid of parallel-plate capacitor. (06 Marks)
OR
8 a. Explain the effect of frequency on. gate voltage of a MOS capacitor with a P-type substrate.
(10 Marks)
b.
Explain P-channel enhancement and depletion type MOSFET with their circuit symbols.
(10 Marks)
Module-5
9 a. . With schematic diagram, explain ION-implantation system. (07 Marks)
b. Explain low pressure chemical vapour deposition reactor. (07 Marks)
c. Discuss photolithography.
(06 Marks)
OR
10 a. What are the different types of integrated circuits and its advantages? (10 Marks)
b. Explain the process of Integration. (10 Marks)
2 of 2
V
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This post was last modified on 02 March 2020