ELECTRONICS COMMUNICATION ENGINEERING II
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INDIAN SPACE RESEARCH ORGANISATION
1 oi= 11
2008 SET-
1. The circuit shown in figure is a
Low-pass filter
High-pass filter
Band-pass filter
Band-reject filter
Yin
R
c
R
Vout
2. In the op-amp circuit given in figure, the load iL is

R2

RL
v

R2
v

R1
3. An op-amp has an offset voltage of 1 mV and is ideal in
all other respects. If this op-amp is used in the circuit
shown in figure, the output voltage will be
ImV
(c)±lV
IV
OV
1Mn


4. For the circuit shown above if gm =3xl 0-3 and
Rs =30000, then the approximate value of Ro is
30000
3000
1000/30
1000
Vs




ELECTRONICS COMMUNICATION ENGINEERING II
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INDIAN SPACE RESEARCH ORGANISATION
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2008 SET-E
5. Where does the operating point of a class-B power amplifier lie?
At the middle of G.C load line
Inside the collector cut-off region on G.C
load line
Approximately at collector cut-off on both the d.c
and G.C Ioadlines .
At the middle point of d.c load line
6. The Laplace transform of e -2t is
1

2s
2

s
2

s+l

s+2
7. The system with characteristic equation s 4 3s3 6s2 9s +12
Stable Unstable Marginally stable
Marginally
unstable
8. Compared to field effect photo transistors, bipolar photo transistors are
More sensitive and faster Less sensitive and slower
More sensitive and slower' Less sensitive and faster
9. The output V-I characteristics of an enhancement type MOSFET has
Only an ohmic region
Only a saturation region
An ohmic region at low voltage value followed by a saturation region at higher voltages
An ohmic region at large voltage values preceded by a saturation region at lower voltages
10. Which ofthe following relation is valid?
Where MTBF =Mean Time Between Failures
MTTF =Mean Time To Failures
MTTR =Mean Time To Repair
MTBF =MTTF MTTR
1 1
MITR . MTTF MTBF
MTTR MTTF MTBF
MTBF.MTTF.MTTR
"
11. Two transistors have the same value of a but different gain bandwidth products. One of them
is a germanium transistor and the other is a silicon transistor. Both the transistors have similar
geometries and base width. The transistor with lower GB product
is the germanium
both are same
is the silicon
Cannot be identified unless more information is
available
12. The following transistor configuration has the highest input impedance
CC CE CB All ofthe above

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2008 SET-E
13. If t hand t m specify the cache access time, hit ratio and main memory access time then the
average access time is (given t c 160ns, t m=960ns h=0.90)
(a)160 ns 960 ns 256 ns 960xO.9 ns
Higher capacity
14. The advantage ofwrite (copy) back data cache organization over write through organization is
Main memory consistency Write allocate on write miss
Less memory bandwidth
requirement
15. E2PROM storage element is
Cross coupled latch
Capacitor
Isolated gate transistor
Flip flop
16. The modulus of cosa i sin a is
2sin a
2
a
2cos2
sm• 2 -a21.
·2 a
cos
2
17. The 8 bit DAC produces 1.0 V for a digital input of 00110010. What is the largest output it can
produce? .
5V -5V (c)5.5 V (d)5.10V
18. The fastest ADC among the following is
Successive approximation type Dual slope type
Sigma -Delta ADC Flash converter
19. The mod number of a Johnson counter will be always equal to ••..•. the number of flip flops·
used
(aj same
2 N where N is the number of flip flops
twice
None ofthe these
20. Odd parity generator uses •.••.••.•... logic
(a)XNOR (b)XOR Sequential OR
21. Which type ofmemory has fast erase and write times
EPROM EEPROM Flash memory None ofthese
22. The performance gain that can be obtained by improving some portion of a computer can be
calculated using
Moore's law
Amdahl's law
Djikstra's algorithm
Murphy's law

ELECTRONICS COMMUNICATION ENGINEERING II
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INDIAN SPACE RESEARCH ORGANISATioN.
40F 11
2008 E
23. Microprogramming refers to
Emulation
The use of storage to implement the
control unit
Programming at micro level
Array processing
24. An array processor is a machine
SIMD (b)MIMD SISD . MISD
25. machines tend to make use ofinternal resources of the processor, a rich set of
registers and a pipelined organization.
else Parallel processor, RISe Array processor
26. Difference between a switch and Hub
Both are same
Hub avoids broadcast
Switch avoids flooding
None ofthe above
27. 100 Base T refers to
Fibre connectivity BNe connectors SONET Twisted pair
28. A S-R flip flop with a clock input can be converted to a flip flop using

Two inverters
One inverter
the flip flop outputs connected to its inputs

Not possible
29. An 8 bit ADe has a full scale input of 2.55 V. Ifother cumulative errors are 2.55 mV,
determine the maximum error
....., ......
10 mV 12.55 mV 7.45 mV 2.55 mV
30. A counter is designed with six stages of flip flops. Determine the output frequency at the last
(sixth) stage, when input frequency is 1 MHz.
1 MHz 166 KHz 15.625 KHz zero
31. The ethernet protocol uses
eSMA/CA SCPC eSMA/CD Slotted ALOHA
32. The value of c which makes the angle 45° between a=i cj and b j is
1 .
1 .J2 -.fi 0

,2008
INDIAN SPACE RESEARCH ORGANISATION
ELECTRONICS COMMUNICATION ENGINEERING II
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SET-E
33. In a daisy chained connection to the CPU, the peripheral whose interrupt request has the
highest priority is the one
With the largest vector address
Electrically nearest to the CPU
34. RS-232 interface
Uses only positive voltage
Uses only negative voltage
With highest speed of operation
Electrically farthest from the CPU
Cannot transmit signals over long distance
A logic high uses positive voltage
35. Assuming ideal conditions,the speed up obtained from a balanced N stage pipeline is
2N
36. The number of comparators required in an 8-bit flash-type AID converter is
256 255 9 8
37. Minimum number of2-input NAND gates that will be required to implement the function:
Y =AB+CD EF is
4 5 6 7
38. In a ripple counter how many changes in state happen when count changes from 7 to
2 4
39. A programmable device (pROM) is
programmable OR and fixed
AND array
programmable AND and
programmable OR array
programmable AND and fixed OR array
none
40. In asynchronous circuits, which ofthe following best explains a dynamic h'azard
Output changesseveral times for a single change in an input
Output changes to a different state for a single change in an input "
Output changes momentarily when it is supposed to remain constant for a single change in an
input
None ofthe above
41. Digital signal processors use a computer architecture derived from
Harvard Architecture Von-Neumann Architecture
Cray Architecture None ofthe above

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wm
60F 11
2008 SET-E

X Z
D Flip
Clock Flop
.
Logic I D
"I flip-flop
Df".." •• J
x

Logic rz-.
42. Which of the following represents the Moore model for sequential circuits?

43. An anti-aliasing filter is
An analog filter A digital filter
Can be analog or
digital
None ofthe above
44. Which of the following filter has the fastest roll-off?
R-C Bessel· Butterworth Chebyshev
45. . Jr) Find the rIllS value of the signal 5 cos SOt
J5 .J5x50t . RoJr
3
.J1'2.5
46. Determine the value indicated by a DC voltmeter for the waveform given below
A
10V
5V
o 10 20 30 40 50 60
Microseconds
OV 2.5 V 10 V 5 V
47. <Xl
Evaluate the function Jt 20{t 3)cit
o
3
!.3

9

o

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2008 SET-E
34
35
48. A husband and wife appear in an interview for two vacancies for same post. The- probability of
husband getting selected is while the probability of wife getting selected is Then the
5 7
probability that anyone of them getting selected is
3
1
5
High bandwidth Voltmeter
49. The rms value of Complex waveforms are measured using
Transistor Voltmeter Differential Voltmeter
Voltmeter containing heat sensing elements such as
es
50. Find the fundamental period T of the following continuous signal
Jr
xCt) =20 cos(1
6
Jr 20x10Jr 5sec
-sec sec
6 T
1 .
-sec
5
51 In the circuit shown the switch closes at t=O. The voltage
across 4jiF capacitor in ideal condition changes to
0
15 V
16 V
24 V

2pF T
53 The network shown in the figure draw a current I. Ifthe ends a
and b are shorted, the current drawn would be
52. The part network of Fig A has open circuit impedance
parameters given by matrix

RR RR]
6 I
2 I

0R RO]
4 I
I.

R00 Roo]
fR




54. As compared to a ful!-wave rectifier using two diodes, the four diode.bridge rectifier has the
dominant advantage of
higher current carrying capacity lower peak inverse voltage
lower rjpple factor higher efficiency
Electronics _II
E
ELECTRONICS COMMUNICATION ENGINEERING II
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wm:r.o INDIAN SPACE RESEARCH ORGANISATION
80F 11

2008 SET-E
55. When a unit impulse voltage is applied to an inductor of 1 H the
energy supplied by the source is
00
1

2
1J
0
lH
56 The value of R for i =2A is
5
40
10
60
5 10
tfl0AG3.ov
57. The time constant for the circuit shown below is
0.2 microsecond
0.8 millisecond
0.4 millisecond
0.2 millisecond
58. For a sinusoidal input, the circuit shown in the figure
will act as a
Pulse generator
Ramp generator
Full-wave rectifier
Voltage doubler


"
59. A second-order band-pass active filter can be obtained by cascading a low pass second order
section having cut off frequency fon with a high pass second order section having cut-off
frequency fOL provided
fOR> f OL fOR f OL fOR OL 1
fOR 5:2fOL
60. If a =0.995, IE 10 rnA and Ico 0.5 f..l then IcEO will be
100 f..l A 10.1 rnA f..l A . 10.5 rnA
....,....-
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2008 SET-E
61. A programme having features such as data abstraction, encapsulation and data-hiding,
polymorphism inheritance is called
Structured programme
Open source programme
Object oriented programme
Real time programme
62. The library function exit causes as exit from
the loop in which it occurs the block is which it occurs
the functions in which it occurs the programme in which it occurs
63. The "go to statement" causes control to go to
An operator A label A variable A function
64. The differential equation satisfying y e3x B e2x is
d 2y -dy

dx2 . dx
d 2 dy

dx dx
d 2y dy

dx2 dx
d 2ydy

dx 2 dx
65. For an energy signal and its time-shifted versionf(t-T),the
amplitude spectra are identical and their"phase spectra are also identical
amplitude spectra are identical but their phase spectra are different
amplitude spectra are different but their phase spectra are identical
amplitude spectra and their phase spectra are different
66. As the modulation index of an FM signal with sinusoidal modulation is increased from zero
the power in the carrier component will
Decrease continuously
First increase, becomes zero and then
decrease
Increase continuously
First decrease, become zero and then increase
67. For a short wave radio link between two stations via the ionosphere, the ratio ofthe maximum
usable frequency to the critical frequency
is always less than 1
is always greater than 1
May be 1 depending on the distance between the
two stations
Does not depend on the distance between the two
stations


ELECTRONICS COMMUNICATION ENGINEERING II
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2008 'SET-E.
68. A carrier voltage is simultaneously modulated by two sine waves causing modulation indices of
0.4 and 0.3. The overall modulation index is
0.35
0.5
0.7
Can not be calculated unless the phase relations are
known
69. If each stage has a gain of 10 dB, and noise figure of 10dB, then the overall noise figure of a
two-stage cascade amplifier will be
10 1.09 1.0 10.9
70. De- emphasis Circuit is used(
To attenuate high frequencies
To attenuate midband frequencies
To attenuate low frequencies
None ofthe above
71. An amplifier has an input power of 2 microwatts. The power gain of the amplifier is 60 dB. The
output power will be
6 microwatts 120 microwatts 2 milliwatts 2 watts
72. A transmission line has a VSWR of the reflection coefficient is
1

3
0
1

73. Which vacuum based device is widely used as a power amplifier in satellite communication
systems?
Amplitron Klystron Magnetron TWT

74. Maxwell's equations establish the relationship between and B at'any point in a
continuous medium. When we move from one medium to another, then which of the following
statement is correct "
At the boundary separating the two media, the tangential components of E and H
continuous
At the boundary separating the two media the tangential components of only E are
continuous
If there are surface charges present on the boundary then normal component of D is
continuous
If there are no surface charges then normal component of D is discontinous

75. The input impedance of short circuited lossless line of length less than a quartevwavelenth is
Purely resistive Purely inductive Purely capacitive Complex

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2008 SET-,E
76. The intrinsic impedance of free space is 377 Q. The approximate intrinsic impedance of a
medium with relative premittivity and permeability of 4 and 1 respectively will be
750 94Q 1880 377Q
77. A 8 kHz communication channel has an SNR of30 dB.lfthe channel bandwidth is doubled,
keeping the signal power constant" the SNR for the modified channel will be
27 dB 30 dB 33 dB 60 dB
78. Two orthogonal signais Sl and S2 satisfy the following relation
nSl 0 g Sl 1
Sl Sl 7r
79. In which modulation system, when modulating frequency is doubled, the modulation index also
becomes double.
AM PM None ofthe above
80. The matrix is its own adjoint. The value of x will be
5


1 0
4 4



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