Download AKTU B-Tech 3rd Sem 2015-2016 EEC 301 Fundamentals Of Electronics Devices Question Paper

Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 3rd Semester (Third Semester) 2015-2016 EEC 301 Fundamentals Of Electronics Devices Question Paper

Printed Pages: 4 427 . EEC-301
(Following Paper ID and Roll No. to be ?lled in your
' Answer Book)
Roll No.
B.Tech.
(SEM. III) THEORY EXAMINATION, 2015-16
FUNDAMENTALS OF ELECTRONICS DEVICES
[Time:3 hours] _ [Total Marks:100]
Section?A
1. Attempt all parts. All pans carry equal marks. Write
answer of each part in short. (2x10=20)
(a) What is degenerate semiconductor?
1675
(i)
(g)
Why metal semiconductor contacts are faster than
that of conventional diode? I
Differentiate direct and indirect bandgap
A semiconductors.
What is ionized impurity scattering.
How~ the effect of ionized impurity scattering is
minimized in high electron mobility transistOrs?
Why 4th quadrant is preferred for solar ?ells?
What is ?orescence?
(1) P.T.O

(h) Comment over the conductivity of semiconductor
at OK -
(i) De?ne minority carrier dif?lsion length.
(j) Why F enni energy level moves toward the middle
of energy gap with increasing temperature.
Section-B
Attempt any ?ve Questions. from this section. (lOXS=50)
2.
I 675
Describe the Hall experiment in detail. Consider a
semiconductor bar of length 10" cm, width 10'2 cm and
thickness 10'3 cm. External applied voltage and resulting
current (1)) are 12.5V and lmA respectively. Magnetic
?eld ap" lied in z-direction have intensity of 5 X 10'2 tesla.
Calcula e the majority carrier concentration and mobility
ifHall .x/oltage is VH=-6.25mV.
Derive the equation?governing the carrier flow
mechanism under the in?uence of electric ?eld?
I
Describe the excess carrier generation through photonic
excitation in semiconductors. Derive the relation of I
!
transmitted and bsorbed power. A 0.46 y m thick sample
of GaAs is illflminated with monochromatic light
hv=2ev. The absorption coef?cient a is 5X104cmj?. The
power incidenl:n sample is lOmW, Calculate: f
a) total ener absorbed by sample per second.
(2) EEC-301
b) Rate of excess thermal energy given up by
electrons to the lattice before recombination.
c) number of photons per second given off from
recombination events, assuming perfect quantum
efficiency. '
Derive the diffusion current density equation. Also, '
derive the equation relation the mobility and diffusion
coef?cient of semiconductor sample.
With the help,ofneat diagram describe the operation of
IGFET. 7
Describe the transient variation of currrent, voltage and
minority carrier pro?le for a P+N diode if it is exited by
a square wave.
With the help of neat diagram describe the operation of
Tunnel diode.
Explain the V-I characteristics of a photodiode. What is
the signi?cance of third and fourth quadrant operation
of photodiode?
Section-C
Attempt any two questions from this section. (15x2=30)
10. Discuss the founation of PN junction diode. Derive the
equation of contact potential and depletion region width
for P+N diode.
(3) p.10.

b 11. Describe the constructional feature of Bipolar Junction
Transistor. Describe various current components and
ampli?ation ratios. Also, mention the base current
controls mechanism.
12. Describe in detail the operation of Shockley diode. Also,
describe various triggering mechanism. '
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