do not open this test booklet until you are asked to do so test booklet · pdf...

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DO NOT OPEN THIS TEST BOOKLET UNTIL YOU ARE ASKED TO DO SO

Test Booklet Series

TEST BOOKLET Electronics AND Telecommunication Engineering (Objective Type) PAPER-II

Time Allowed: Two Hours Maximum Marks: 200

INSTRUCTIONS

1. IMMEDIATELY AFTER THE COMMENCEMENT OF THE EXAMINATION YOU SHOULD

CHECK THAT THIS TEST BOOKLET DOES NOT HAVE ANY UNPRINTED OR TORN OR

MISSING PAGES OR ITEMS ETC. IF SO, GET IT REPLACED BY A COMPLETE TEST

BOOKLET.

2. ENCODE CLEARLY THE TEST BOOKLET SERIES A, B, C, OR D AS THE CASE MAY BE IN

THE APPROPRIATE PLACE IN THE ANSWER SHEET.

3. You have to enter your Roll Number on the

Test Booklet in the Box provided alongside.

DO NOT write anything else on the Test Booklet.

4. This Test Booklet contains 120 items (questions). Each item comprises four responses (answers).

You will select the response which you want to mark on the Answer Sheet. In case you feel that there

is more than one correct response, mark the response which you consider the best. In any case,

choose ONLY ONE response for each item.

5. You have to mark all you responses ONLY on the separate Answer Sheet provided. See directions in

the Answer Sheet.

6. All items carry equal marks.

7. Before you proceed to mark in the Answer Sheet the response to various items in the Test Booklet,

you have to fill in some particulars in the Answer Sheet as per instructions sent to you with your

Admission Certificate.

8. After you have completed filling in all your responses on the Answer Sheet and the examination has

concluded, you should hand over to the Invigilator only the Answer Sheet. You are permitted to take

away with you the Test Booklet.

9. Sheets for rough work are appended in the Test Booklet at the end.

10. Penalty for wrong answers:

THERE WILL BE PENALTY FOR WRONG ANSWERS MARKED BY A CANDIDATE IN THE

OBJECTIVE TYPE QUESTION PAPERS.

(i) There are four alternatives for the answer to every question. For each question for which a

wrong answer has been given by the candidate, one-third (0.33) of the marks assigned to that

question will be deducted as penalty.

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of the given answers happens to be correct and there will be same penalty as above to that

question.

(iii) If a question is left blank, i.e., no answer is given by the candidate, there will be no penalty

for that question

DO NOT OPEN THIS TEST BOOKLET UNTIL YOU ARE ASKED TO DO SO


I (mA)D

8

–4V (volt)GS

200ohm 1k

vo18v

RLvin

+

–

IC2IC1

+5V

–

+

–

+

R3

R1

R2Rcomp

vo

C4

R4

R

C

1. For given JFET characteristic shown below:

What is the maximum value of Trans conductance gain?

(A) 2 ms (B) 4 ms (C) 8 ms (D) Data insufficient

2. For given regulator circuit what is the value of Zener diode current??

If zV 12 volt and 55

(A) 11.3 mA (B) 17.6 mA (C) 29.8 mA (D) 30 mA

3. A voltage of v 1 2sin t is applied to the circuit shown below. The capacitor C and diode are

considered as ideal and RL is the resistance of large value. what is the magnitude of average voltage

across RL ??

(A) –4 (B) +4 (C) –2 (D) +2

4. For the current mirror circuit shown in figure, what is the value of 2CI if two transistors are identical

and 25

(A) 23.2 A (B) 24.2 A (C) 25.2 A (D) 26.2 A

5. What is the output of OPAMP based waveform generator shown in figure:

(A) Square wave (B) Rectangular wave (C) Triangular wave (D) Impulse


–

+

R

vo

100k

10kV

–

V+

–

+

R1

vo

RS

R2 RL

+–Vs

Cox

Vth

VGS

VFB

+–

RC

VCC

2V

–

+

R1

R2

R3 I2

I1

+

–

V1

+

–

V2

6. In the given circuit if voltage inputs V– and V

+ are to be amplified by same amplification factor then

value of resistance ‘R’ should be :

(A) 145 k (B) 150 k (C) 155 k (D) 160 k

7. Assume that the OPAMP shown below has infinite input resistance and zero output resistance. If

open loop voltage gain = 104 then calculate value of 2 1R /R to obtain a closed loop gain of 10

(A) 9.01 (B) 8 (C) 0.9 (D) 90

8. The graph of MOS capacitance vs. voltage shown below is:

(A) High frequency C-V curve (B) Low frequency C-V curve

(C) Both high frequency & Low frequency C-V curve (D) None

9. What is the value of input impedance for circuit shown below? BEV 1volt (β=49)

(A) 4.9k (B) 2.45k (C) 9.8k (D) 3.0k

10. For the given Ideal OPAMP circuit what is the value of Y11 and Y12 parameters for given [Y] matrix?

(A) 11 12Y 0 & Y 0 (B) 11 12Y 1 & Y 1

(C) 11 12Y 1 & Y 1 (D) 11 12Y 1 & Y 0


CERE

CC

CR R

R2

R1

RC

VCC

VDD

Vout

Vin

+

-v0

R

R

C

C

vi

11. Given below is RC phase shift oscillator using BJT then for the loop gain to be greater than unity

current gain of transistor should be: (For RC = R)

(A) > 29 (B) < 29 (C) > 56 (D) < 56

12. If length (L) of MOSFET increases then voltage of amplifier shown below:

(A) Decreases (B) Increases (C) Remains constant (D) becomes zero

13. A negative feedback is applied to an amplifier with the feedback voltage proportional to output

voltage this feedback increases the:

(A) Input impedance of amplifier (B) output impedance of amplifier

(C) Distortion in the amplifier (D) Gain of amplifier

14. For a given filter order which one of the following type of filters has the least amount of ripple both

in pass band and stop band?

(A) Chebyshev type-I (B) Bessel (C) Chebyshev type-II (D) Elliptic

15. A BJT Darlington pair has:

(A) High input impedance and high value of Beta (B) High input impedance and low value of Beta

(C) Low input impedance and high value of Beta (D) Low input impedance and low value of Beta

16. Adding a degeneration resistor RE to a common emitter BJT amplifier will mainly:

1. Increases the voltages gain 2. Decreases the voltage gain

3. Increases the input impedance 4. Improve stability and increases bandwidth

Which of the following statements are correct?

(A) 1, 2 & 3 (B) 2, 3 & 4 (C)1,3 & 4 (D) 1, 2, 3 & 4

17. The circuit shown in figure below represents:

(A) Inverting integrator

(B) Band pass filter

(C) All pass filter

(D)Non-inverting integrator


12V

5V

•

A

B

C

D

VCC

Y

Q

RP

S

LED

EX–NOR O/P

1

0

1

0

2×1 MUX

2×1 MUX

B

B

A

18. Given circuit behaves as:

(A) Constant voltage source

(B) Current Mirror

(C) Regulator

(D) Constant current Source

19. For the given diode circuit the output Y is

(A) A B C D

(B) AB + CD

(C) AB CD

(D) ABCD

20. For the switched circuit shown below taken open as ‘0’ and closed as ‘1’ the expression for the

circuit when LED glows is:

(A) P Q R S (B) P QR S (C) P QR S (D) LED will not glow

21. For design of 256 1 MUX how many 8 1 MUX are required

(A) 36 (B) 37 (C) 32 (D) 33

22. For a 2 stage operation of 2 1 MUX shown below the final output Y will be:

(A) 0

(B) 1

(C) A B

(D) AB


b7 b6 b5 b4 b3 b2 b1 b0

D Q

CLK

23. A J-K Flip flop can be made from an S-R Flip flop by using two additional

(A) AND Gates (B) OR gates (C) NOT gates (D) NOR gates

24. The Boolean expression AB AB is logically equivalent to which of the following?

1. (A B).(A B) 2. (A B).(A B)

3. (AB AB) 4. (A.B).(A.B)

Select the correct answer using the codes given below:

(A) 1 & 2 (B) 2 & 4 (C) 1 & 3 (D) 1, 2 & 3

25. Which of the following notations have two representations of zeros?

1. 1’s complement with radix of number being 2




(A) 1, 2 & 4 (B) 1 & 3 (C) 2, 3 & 4 (D) 1, 2 & 3

26. Consider the following multiplication 2 10 2(10w1z) (15) (y01011001) which one of the following

set of w, y and z gives appropriate values:

(A) w = 0, y = 0 and z = 1 (B) w = 1, y = 1 and z = 0

(C) w = 0, y = 1 and z = 1 (D) w = 1, y = 1 and z = 1

27. Which one of the following will give carry of the sum of full adder as output?

(A) Three input majority circuit (B) Three bit parity checker

(C) Three bit comparator (D) Three bit counter.

28. The minimum no. of 2 inputs NAND gates required to implement a 4 input NAND gates are

(A) 2 (B) 3 (C) 4 (D) 5

29. If 8-bit shift register and D FF shown in fig. are synchronized with same clock, if D FF is initially

cleared and 8-bit shift register contains B7 then after 4 clock pulses content of register will be:

A. 73

B. 72

C. 74

D. 7E


A

A

A

A

A

A

A

A

A

A

9

8

7

6

5

4

3

2

1

0

A

A

A

A

A

A

15

14

13

12

11

10

CS

1 KBMemory

Chip

1

1

A B C

30. Consider a memory chip with 1024 bytes storage connected to a 8085 chip address lines (or any

microprocessor with 16 address lines) as above. What is the range of memory address?

(A) 0000 H to 03 FFH (B) 8000 H to 83 FFH (C) F000 H to F3FF (D) 0000 H to FFFFH

31.

The counter shown in figure is

(A) MOD-8 up counter (B) MOD-8 down counter

(C) MOD-5 down counter (D) MOD-6 down counter

32. Consider the following statements in respect of ECL gate:

1. Its switching speed is high

2. It provides OR and NOR operation

3. Its power dissipation is small as compared to other logic gates

4. Its logic level is not compatible with other logic family because it uses negative power supply


(A) 1 & 2 (B) 1, 2 & 3 (C) 1, 3 & 4 (D) 1, 2 & 4

33. Consider the following statements regarding Latch and Flip flop:

1. Flip flop is bi stable while latch is mono stable

2. Flip flop is edge triggered while latch is level triggered

3. In Flip flop output is determined by clock signal and in case of latch output is independent of

clock


(A) 1 & 2 (B) 2 & 3 (C) 1 & 3 (D) 1, 2 & 3

34. A ripple counter is to operate at a frequency of 10MHz.If propagation delay time of each flip flop in

the counter is 10 ns and the strobing time is 50 ns how many maximum stages can the counter have?

(A) 10 (B) 5 (C) 210

(D) 102


35. MOD-11 ripple counter consists of 4 Flip-flops and a combinational circuit then economical

combinational circuit will be:

(A) 4 input AND gate (B) 4 input NAND gate

(C) 3 input OR gate (D) 3 input NOR gate

36. In a weighted register DAC with 8 bit input if the resistance corresponding to MSB is 2K what will

be the resistance corresponding to LSB?

(A) 250 ohm (B) 512 K ohm (C) 256 K ohm (D) 25.5 ohm

37. The minimized form of Boolean expression f (A,B,C) (0,2,3) is:

(A) A BC (B) A BC (C) AC B (D) ABC AB

38. In a dual slope type digital voltmeter, an unknown signal voltage is integrated our 100 cycles of

clock. If the signal has a 50 Hz pick up the maximum clock frequency can be:

(A) 50 Hz (B) 5 kHz (C) 10 kHz (D) 50 kHz

39. Consider the following statements in connection with the feedback of control system:

1. Feedback can improve stability or be harmful to stability if not properly applied

2. Feedback can always improve stability

3. In many situations the feedback can reduce the effect of noise and disturbance on performance of

system

4. In general sensitivity of the system gain of feedback system to a parameter variation depends

upon where the parameter is located.


(A) 1, 2 & 3 (B) 1, 3 & 4 (C) 1, 2 & 4 (D) 1, 2, 3 & 4

40. When a transfer function model is converted into state space model the order of the system may be

reduced during which one of the following conditions?

(A) Some of the variables are not considered (B) some of the variables are hidden

(C) Pole zero cancellation will takes place (D) The order of the system will get changed

41. Consider the following:

1. Rise time 2.Settling time

3. Delay time 4. Peak time

What is the correct sequence of the time domain specifications of a second order system in the

ascending order of values?

(A) 2-4-1-3 (B) 3-4-1-2 (C) 2-1-4-3 (D) 3-1-4-2

42. Which one of the following is not the effect of adding a zero to the system?

(A) Band width is increased and system becomes relatively more stable

(B) Root locus goes away from jw axis

(C) Settling time is decreased and rise time is also decreased

(D) Steady state error value is also decreased

43. The system with open loop transfer function 2

1( ) ( )

( 1)G s H s

s s s

has a gain margin of

(A) 0 dB (B) -3 dB (C) +3 dB (D) -6dB


Log

F 1 2 3 4 1 C

–1–1–1

5

44. The phase V’s frequency plot shown below is that of a

(A) PID Controller θ

(B) Phase Lag lead network

(C) PD Controller

(D) PI Controller

45. Which statements are true for a counter clock wise Nyquist path?

1. For a stable closed loop system Nyquist plot of G(s) H(s) should encircle (–1, j 0) point as many

as times as there are poles of G(s) H(s) in right half of s-plane the encirclement if there are any

must be made in counter clock wise direction.

2. If open loop gain is stable then closed loop system is always not stable

3. If loop gain G(s) H(s) is a stable then for a stable closed loop system Nyquist plot of G(s) H(s)

must enclose critical pt. (-1, j0)

(A) 1, 2 (B) 2, 3 (C) 1, 3 (D) 1, 2, 3

46. Which of the following is correct?

The slope of the asymptotic Bode magnitude plot is integral multiple of:

(A) 40 dB/decade (B) 12 dB/octave (C) 6 dB/octave (D) 3 dB/octave

47. In the signal flow graph of figure the gain C/R will be:

(A) 11/9 (B) 22/15 (C) 24/23 (D) 44/23

48. Match List-I with List-II and select the correct answer by using the codes given below the lists:

List-I List-II

A. Synchro

B. Amplidyne

C. Servo

D. RC Network

1. Amplifier

2. Actuator

3. Compensator

4. Transducer

Codes: A B C D

(A) 1 2 3 4 (B) 4 3 2 1

(C) 3 2 4 1 (D) 4 1 2 3

49. For two phase a.c. servomotor if the rotor’s resistance and reactance are respectively R and X its

length and diameters are respectively L and D then:

(A) Both X/R and L/D are small (B) X/R is large but L/D is small

(C) X/R is small but L/D is large (D) Both X/R and L/D are large


(-1, 0)× × ×

0

0

J

Im

Re

50. The open loop transfer function of a closed loop control system is given by

2

( 2)( ) ( )

( 1)( 4)

K sG s H s

s s s

what are the number of asymptotes and the centroid of the asymptotes of

the Root loci of closed loop system?

(A) 7

3, ,03

(B) 7

2, ,03

(C) 3, 2,0 (D) 2, 2,0

51. A second order control system has a transfer function 2

16

4 16s s what is the time for the first

undershoot peak?

2

( ) sec ( ) sec ( ) sec ( ) sec3 3 2 3 4 3

A B C D

52. What is the value of phase Margin of a system with open loop transfer function

(1 )G ( ) ( )

(1 )(2 )

ss H s

s s

is:

(A) 0º (B) 63.4º (C) 90º (D)

53. The pole-zero map and Nyquist plot of a open loop transfer function are shown in figure then

(A) Both open and closed loop systems are stable (B) Open loop is stable, but closed loop unstable

(C) Open loop is unstable but closed loop stable (D) Both open loop and closed loop are unstable

54. For a given system whose Nyquist plot is shown in figure determine Type and order of system?

(A) Type 2 Order 1 (B) Type 0 order 2 (C) Type 2 Order 2 (D) Type 1 order 2

55. When all the elements in one row of the Routh’s tabulation are zero then this condition indicates:

1. One pair of real roots with opposite sign in s-plane

2. One pair of conjugate roots on the imaginary axis in s-plane

3. Conjugate roots forming a quadrature in s-plane


(A) 1 only (B) 2 only (C) 3 only (D) 1,2&3


56. The state equations of a system are given by:

.3 1 0 0

0 3 0 0

0 0 1 0

1 0 1

x x u

y x

Then given system is:

(A) Controllable and observable (B) Controllable but not completely observable

(C) Neither controllable nor observable (D) Observable but not completely controllable

57. Consider the root loci plots which of the following Root locus is not valid one

(A) (B)

(C) (D)

58. Which of the following statements are true about Bode Plot?

1. For Minimum phase plot phase angle varies from 0 to -90 degree

2. For Non-Minimum phase plot phase angle varies from 0 to -270 degree

3. For all pass phase plot phase angle varies from 0 to -180 degree.

(A) 1 & 2 (B) 2 & 3 (C) 1 & 3 (D) 1, 2 & 3

59. In AM receiver operating with a sinusoidal modulating signal and 50% modulation has an output

SNR of 30 dB. What is the value of carrier to noise ratio.

(A) 1000 (B) 2000 (C) 3000 (D) 4000

60. A rectangular pulse train of time period 0.1 m sec. is multiplied with signal cos (8 π × 103 t) then

multiplied signal will be a

(A) DC (B) Sinusoid of 12 kHz (C) Sinusoid of 14 kHz (D) Sinusoid of 8 kHz.

61. An image used 12 × 512 picture elements. Each of the picture elements can take any of the 8

distinguishable intensity levels. The maximum entropy in the above image will be:

(A) 2097152 bits (B) 18432 bits (C) 684 bits (D) 144 bits

62. What is Hilbert transform of x (t) = sin 2 ω0 t + cos 2 ω0 t

0 0 0 0

0 0 0 0

A 2 cos 2 t- 2 sin2 t B cos 2 t – sin2 t

C cos2 t - sin2 t D – cos2 t sin2 t


63. A discrete source produces 8 symbols and is memory-less. Its entropy is

(A) 1 bit/symbol only (B) 2 bits/symbol only

(C) 3 bits/symbol only (D) 3 bits/symbol

64. A communication channel has a bandwidth of 100 MHz. The channel is extremely noisy such that

the signal power is very much below the noise power. What is the capacity of this channel?

(A) 100 Mbps (B) 50 Mbps (C) 2400 bps (D) Nearly 0 bps

65. Which of the following are not characteristics of line code?

(A) Timing recovery (B) Echo cancellation

(C) Non favorable PSD (D) Easy implementation

66. The power spectral density of deterministic signal is given by

2sin f

f

where f is the frequency:

The Autocorrelation function of the signal in time domain is:

(A) A rectangular pulse (B) A delta function (C) A sinc pulse (D) A triangular

67. If a band pass signal is in the frequency range of (12-16 kHz) then sampling frequency of signal in

frequency domain is

(A) 8 kHz (B) 24 kHz (C) 28 kHz (D) 32 kHz

68. A device with input x(t) and output y(t) is characterized by y(t)=x2(t). An FM signal with frequency

deviation of 90 KHz and modulating signal bandwidth 5 KHz is applied to this device. What is

bandwidth of the output signal?

(A) 370 KHz (B) 190KHz (C) 380 KHz (D) 95 KHz

69. A signal with 5V, ranged and 1 kHz bandwidth is being digitized using a sample and Hold circuit,

if a 5-bit quantize is used, then what is the minimum value of sampling rate.

(A) 31416 V/sec (B) 62831 V/sec (C) 15708 V/sec (D) 5000 V/sec

70. What is peak amplitude of output of a matched filter for a signal?

A, 0 < t < 1 m sec

s(t) =

0, 1ms < t <1.4 ms

If value of peak amplitude A is given as 1.0 volt

(A) 1 mV (B) 2/3 mV (C) 2 mV (D) 1/3 mV

71. In case of AM detection by linear diode detector or envelop detection diagonal clipping can be

avoided by

1. Increasing modulating frequency

2. Decreasing Modulating frequency

3. Decreasing RC time constant.

(A) 1, 2 (B) 2, 3 (C) 1, 3 (D) 1, 2, 3

72. A duplexer is used for which one of the following?

(A) To couple two antennas to a transmitter without interference

(B) To isolate the antenna from local oscillator

(C) To prevent interference between two antennas connected to receiver

(D) To use same antenna for reception or transmission without out interference


+-

2 ein

2

+-

+-

3 ein

2

A cos w tc

output

x(t)K73.

In the following figure if x(t) is modulating signal then what is value of K for output to be DSB-SC

signal:

3 2 3 2( ) ( ) ( ) ( )

2 3 2 3A B C D

74. On which bands do the optical fibers operate?

1. Ultra violet band 2. Ultra high frequency band 3. Visible light band 4. Infra red band

Select the correct answer from the codes given below:

(A) 1 only (B) 1 and 2 only (C) 1, 2 and 3 (D) 1, 3 and 4

75. The message signal input to a DM is m(t) = 5 cos(2π × 1000 t) + 2 cos(2π × 2000 t) volt where t is in

sec. Determine minimum value of pulse rate that will prevent slope overload, if step size is 0.314

volt.

(A) 120 kbps (B) 80 kbps (C) 100 kbps (D) 150 kbps

76. Consider the following statements about communication satellite:

1. Band width of 500MHz is allotted

2. They are placed at height of around 36000Km

3. It uses frequency reuse & polarization reuse technique

4. Uplink frequency may be less than down link frequency

(A) 1, 2 & 3 (B) 2, 3 & 4 (C) 1, 3 & 4 (D) 1, 2, 3 & 4

77. Which one of the following frequency bands is allocated by ITU (International Telecommunication

Union) for DBS-Direct Broadcast Service (also referred as DTH-Direct to Home service):

14 6 2 42( ) ( ) ( ) ( )

12 4 1 20A GHz B GHz C GHz D GHz

78. Which of the following does not cause losses in optical fiber cables?

(A) Impurities (B) Micro bending (C) Attenuation in glass (D) Stepped index operation

79. Which mode has the lowest cut off frequency of circular wave guide?

(A) TE11 (B) TE10 (C) TE20 (D) TE21

80. Which modes of circular wave guide have circular symmetry?

(A) TE11 (B) TE11&TE21 (C) TE01 (D) TE01&TM01

81. The air pressure in a rectangular wave guide is increased then maximum power handling capability

(A) is increased (B) is decreased (C) remains the same

(D) May increase or decrease depending upon pressure

82. In microwave circuit a mode transducer is used to:

(A) Change mode of wave transmission (B) change direction of wave transmission

(C) Change polarization of wave transmission

(D) Change mode, direction or polarization of wave transmission


83. A matched generator with 1W available power is connected to H arm of Magic Tee. If all ports are

matched then power delivered at ports 1,2&3 respectively are:

(A) 0.5W,0.5W and 0W (B) 0W,0W and 1W

(C) 0.33 W each (D) 0W,0.25W and 0.25W

84. Power monitor and reflecto meter uses the principle of:

(A) Directional coupler (B) Klystron amplifier (C) Gunn diode (D) TWT

85. If QL is loaded ,QE is external and Qu is unloaded quality factor of micro wave resonator then:

(A) L E U

1 1 1

Q Q Q (B)

E L U

1 1 1

Q Q Q (C)

U E L

1 1 1

Q Q Q (D)

E

L U

1 1Q

Q Q

86. Consider the following statements:

1. Bunching of electrons occur in two cavity klystron amplifier

2. Bunching of electrons occur in multi cavity klystron amplifier

3. Bunching of electrons occur in reflex klystron amplifier


(A) 1 & 2 only (B) 2 & 3 only (C) 1 & 3 only (D) 1, 2 & 3 only

87. In a klystron amplifier the transit time of electrons in passing the gap in cavity should be:

(A) Less than one cycle (B) Less than half cycle

(C) Less than quarter cycle (D) More than quarter cycle

88. Consider the following statements about TWT:

1. It uses thermionic emission

2. It uses an attenuator

3. It is inherently a resonator device

4. It has broad bandwidth


(A) 1, 2 & 3 (B) 1, 2 & 4 (C) 1, 3 & 4 (D) 1, 2, 3 & 4

89. The π mode of operation of magnetron signifies that:

(A) The phase difference between adjacent anode poles is π radians

(B) The phase difference between adjacent anode poles is multiple of π radians

(C) The total phase shift around the periphery is π radians

(D) The total phase shift around the periphery is multiple of π radians

90. Consider the following points about parametric amplifier:

1. It has low noise

2. It has very high gain

3. It has broad bandwidth

Which of the followings are the main features of parametric amplifier?

(A) Only 1 (B) Both 1 & 2 (C) Both 1 & 3 (D) 1, 2 & 3

91. The reverse voltage applied to a Varactor diode:

(A) is less than avalanche breakdown voltage

(B) is more than avalanche break down voltage

(C) May be more or less than avalanche break down voltage

(D) is very high as compared to avalanche break down voltage


92. Which of the following devices has the ‘negative resistance’ characteristic?

(A) Reflex klystron (B) Gunn diode (C) P-N-P transistor (D) Magnetron

93. Which one of the following is a transferred electron device?

(A) BARITT diode (B) IMPATT diode (C) TRAPATT diode (D) Gunn diode

94. In 8085 the instruction CMA is an example of:

(A) Implicit addressing (B) Direct addressing

(C) Register addressing (D) immediate addressing

95. In an 8085 microprocessor based system the contents of SP are 2000H. POPH instruction will

transfer the contents of memory location

(A) 2001 H and 2002 H to H and L register respectively

(B) 2001 H and 2000H to H and L registers respectively

(C) 2000H and IFFFH to H and L registers respectively

(D) 2000H and 1999 H to H and L registers respectively

96. The total number of memory accesses involved (inclusive of the op-code fetch) when an 8085

processor executes the instruction LDA 2003 is:

(A) 1 (B) 2 (C) 3 (D) 4

97. The contents of Register (B) and Accumulator (A) of 8085 microprocessor are 49H and 3AH

respectively. The contents of A and the status of carry flag (CY) and sign flag (S) after executing

SUB B instructions are:

(A) A = F1, CY = 1, S = 1 (B) A = 0F, CY = 1, S = 1

(C) A = F0, CY = 0, S = 0 (D) A = 1F, CY = 1, S = 1

98. The sequence of instructions to complete the program would be

The following program starts at location 0100H.

LXISP, 00FF

LXIH, 0107

MVIA, 20H

SUB M

If the content of accumulator when the program counter reaches 0109H is 00H and if in addition

following code exists from 0109H onwards:

ORI 40H

ADD M

What will be the result in the accumulator after the last instruction is executed?

(A) 40H (B) 20H (C) 60H (D) 42H

99. Which one of the following is a correct statement in connection with commands of CMP and CPI?

(A) CMP takes less number of cycles compared to CPI

(B) CMP takes more number of machine cycles compared to CPI

(C) Both CMP and CPI take the same number of machine cycles

(D) CMP takes either less or the same number of machine cycle as compared to CPI.

100. A Microprocessor uses 3 MHz oscillator then duration of one T state is:

(A) 1 µsec (B) 0.666 µsec (C) 0.333 µsec (D) 3 µsec


101. In a multi processor configuration two coprocessors are connected to host 8086 processors. The

instruction set of two processors

(A) Must be same (B) Must overlap (C) May be disjoint (D) Must be same as that of host

102. Consider the following statements:

1. An assembler is a program having assembly language program as input and machine language

program as output.

2. A Macro assembler is an assembler with additional macro facilities

3. A cross assembler for a MP X is an assembler which executes on source micro computer with a

different CPU than X but generates code for X

4. Assemblers generally don’t provide macro facilities


(A) 1, 2 & 3 (B) 2, 3 & 4 (C) 1, 3 & 4 (D) 1, 2, 3 & 4

103. Expression ++i is equivalent

(A) i = i + 2 (B) i = i + 1 (C) i = i + i (D) i = i + i + i

104. The use of cache in a computer system increases the

(A) Available memory space for the program (B) available memory space for data

(C) Average speed of memory access (D) addressing range of CPU

105. Consider the following:

1. Input device

2. Arithmetic and logic unit

3. Control unit

4. Auxiliary memory

5. Main memory

6. Active hub

Which of these form part of CPU?

(A) 1, 4 and 6 (B) 2, 3 and 6 (C) 2, 4 and 5 (D) 2, 3 and 5

106. Which one of the following is correct?

A micro program is

(A) any source program run on micro computers

(B) any set of instructions for primitive operations in a system

(C) a general name for ‘macros’ used in assembly language programming

(D) any program of a very small size

107. If the HLT instruction of an Intel 8085 microprocessor is executed

(A) The microprocessor is disconnected from the system bys till the RESET us pressed

(B) The microprocessor halts the execution of the program and returns to the monitor

(C) The microprocessor enters into a HALT state and the buses are tri-stated

(D) The microprocessor reloads the program counter form the locations 0024 H and 0025 H

108. The cycle required to fetch and execute an instruction in a 8085 microprocessor is which one of the

following?

(A) Clock cycle (B) Memory cycle (C) Machine Cycle (D) Instruction cycle


Directions (Q Nos. 109 to 120) each of the next twelve (12) items consists of two statements one labeled as

Assertion (A) and other as Reason(R).You are to examine these two statements carefully and select the

correct answers to these items using the codes given below:

Codes:

(A) Both A&R are individually true and R is the correct explanation of A

(B) Both A&R are individually true but R is not the correct explanation of A

(C) A is true but R is false

(D) A is false but R is true

109. Assertion (A): In class C amplifier efficiency is more than that for other classes of amplifiers

Reason(R): In class C amplifier we can get high efficiency over a wide band range

110. Assertion (A): The ac load line is different form dc load line

Reason(R): The ac load resistance seen by collector and emitter is different from dc load

resistance.

111. Assertion (A): Demultiplexer can’t be used as decoder

Reason(R): Multiplexer selects one of many outputs where as a decoder selects an output

Corresponding to a decoded input

112. Assertion (A): In totem pole output the output impedance is low

Reason(R): TTL gate with active pull up should not be used in wired AND connections

113. Assertion (A): The phase angle plot in Bode diagram is not affected by change in system gain

Reason(R): The variation in gain has no effect on phase margin of the system

114. Assertion (A): A synchro control transformer has nearly constant impedance across its rotor

terminals

Reason(R): Rotor of a synchro control transformer is cylindrical so as to give uniform flux

distribution

115. Assertion (A): FM requires more bandwidth than AM

Reason(R): Wide band FM is used for broad cast transmission

116. Assertion (A): In digital communication data is coded prior to being transmitted

Reason(R): A number of codes for digital data processing are available

117. Assertion (A): IMPATT diode can be used in both amplifiers and oscillators

Reason(R): IMPATT diode has a low resistance

118. Assertion (A): Bolometer is frequently used in microwave power measurement

Reason(R): In a bolometer the input microwave power causes change in resistance

119. Assertion (A): Each memory chip has its own address latch

Reason(R): ALE signal comes out of microprocessor 8085 and goes to memory chip

120. Assertion (A): A high level language is less efficient than machine language but more efficient

than assembly language

Reason(R): It is easier to learn and use higher level language than machine language


Answers: ECE Paper-2(Full Mock Test-1)

1 B 31 B 61 B 91 A

2 C 32 D 62 D 92 B

3 C 33 B 63 D 93 D

4 A 34 B 64 D 94 A

5 C 35 C 65 C 95 B

6 B 36 C 66 D 96 D

7 A 37 A 67 A 97 A

8 B 38 B 68 A 98 C

9 B 39 B 69 A 99 D

10 A 40 C 70 B 100 B

11 C 41 D 71 C 101 D

12 A 42 D 72 D 102 A

13 A 43 A 73 A 103 B

14 B 44 B 74 D 104 C

15 A 45 A 75 C 105 B

16 B 46 C 76 A 106 B

17 D 47 D 77 A 107 C

18 D 48 D 78 D 108 C

19 A 49 C 79 A 109 C

20 B 50 A 80 D 110 A

21 B 51 B 81 A 111 D

22 A 52 D 82 D 112 B

23 A 53 B 83 A 113 C

24 C 54 D 84 A 114 A

25 D 55 B 85 A 115 B

26 D 56 D 86 D 116 B

27 A 57 C 87 C 117 B

28 D 58 D 88 B 118 B

29 D 59 D 89 A 119 B

30 B 60 C 90 A 120 D


1. (B) DSS GSm

P P

2I Vg 1

V V

Maximum value of gm value will be DSS

P

2I 2 84mA / V

V 4

2. (C)

Let IL is load current in 1 K ohm resistor and IB is base current in transistor.

L B

R

Z

12 0.7 11.4I 11.3 mA, I 0.205 mA

1K 56

18 12I 30mA

200

I 30 .205 29.8mA

3. (C) Maximum value of vi=3 volt in Positive half D is ON and VC=3Volt& Vo=0 Volt

In negative half D is OFF and voltage across capacitor remains constant

So here

0 0V 1 2sin t 3 2 2sin t Here V 2Volt

4. (A) It is current mirror circuit

2

1 2 2 2

C

C B C C

2I 25 2525 I 2I I I 23.15 A

27

5. (C) It is astable circuit followed by integrator. Output of astable is square wave and integrator will

convert it into triangular wave.

6. (B) 100 R

R 150Kohm10 15

7. (A) It is Open loop opamp which has finite value of gain

f

0 1

fi

1

OL

R1

V R

RV1

R1

A

8. (B) It is low frequency C-V characteristics

9. (B) B BE B2 100I V I 0.01mA

E BI ( 1)I 50 0.01mA 0.5mA

Te

E

V 25mVr 50

I 0.5mA

ie e

i ie

h r 49 50 2.45K

Here R h 2.45 K

10. (A) Here

1 1 11 2 12

11 12

I 0 V Y V Y

Y 0 & Y 0

11. (C)

fe fe

29h 23 4K ( K 1) h 23 4 29

K

12. (A) m

Wg K

L


13. (A)

14. (B) Bessel has zero ripple in Pass band and zero ripple in stop band

15. (A)

16. (B)

17. (D) Just solve by use of Laplace transform and calculate its transfer function

0

i

V 1

V sRC

18. (D) Here IL is independent of Load value and power supply hence it is working as constant current

source

19. (A)

20. (B) For LED glow all should be connected properly and it must work like ‘1’

21. (B)

22. (A) 1 2Y AB AB&Y AB AB Both are complement to each other so output of EXNOR will

be Zero

23. (A)

24. (C)

25. (D) (r 1) complement system will always have two representation of zeros where r is the base

26. (D) Tricky and logical question

27. (A) Three input majority circuit has output AB+BC+AC

28. (D)

29. (D)

30. (B) For Chip to be selected output of NAND gate must be zero

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0A A A A A A A A A A A A A A A A

1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

1 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1

31. (B) It is standard circuit of MOD-8 Down counter

32. (D) Power dissipation in case of ECL is high because it has high speed and product of speed and

power dissipation remains constant.

33. (B) Both FF and Latch are Bistable system

34. (B)

n 10 50 100

n 5

35. (C) Economical combinational circuit for MOD-11 will be either 3 input NAND gate or 3 input OR

gate

36. (C)

37. (A)

38. (B) mMax CLKfreq 100 50Hz 5KHz

39. (B) It is not necessary that feed back will always improve stability it depends upon type of feed back

40. (C)

41. (D)

42. (D) Adding zero means phase lead system and in phase lead steady state error is never decreased

43. (A)

44. (B) It is changing phase in both positive and negative direction.

45. (A) Statement (3) is not correct. If encirclement is there means N=1 Z is not equal to zero

46. (C) 6 dB/octave= 20 dB/decade

47. (D)

48. (D)

49. (C)

50. (A)


51. (B)

2 1p

d

nt n st under shoot

52. (D) There will be no real value of GCF so PM will be infinite.

53. (B)

54. (D)

55. (B)

56. (D)

57. (C) There is no pole and root locus is terminating at zero

58. (D)

59. (D) 2

a

S Cm

N N

60. (C) 4 10f KHz KHz

61. (B) Entropy is measurement of bits 12 512 3Entropy bits

62. (D)

63. (D) 2 2log log 8 3H M It will be its maximum value

64. (D)

2log 1 2S S

C B here is very lowN N

65. (C)

66. (D) Rectangular has F.T of Sinc function so triangular will have convolution of two rectangular and

hence it will be Sinc2

67. (A) It is basically Band pass sampling theorem

68. 2

, ,u uD u l s

D

f ff f f K f

f K

69. (A)

70. (B)

71. (C) For Diagonal clipping 1

m

RC For Diagonal clippingf

72. (D)

73. (A)

74. (D)

75. (C)

76. (A)

77. (A)

78. (D)

79. (A)

80. (A)

81. (A)

82. (D)

83. (A)

84. (A)

85. (A)

86. (D)

87. (C)

88. (B)

89. (A)

90. (A)

91. (A)


92. (B)

93. (D)

94. (A)

95. (B)

96. (D)

97. (A)

98. (C)

99. (D) If CMP R is used then No of machine cycles are 1 but for CMP M no of machine cycles are 2

But in case of CPI machine cycles are always equal to 2.

100. (B) output of clock frequency is 3/2=1.5 MHz so duration of 1 T state is 6

10.67 sec

1.5 10

101. (D) Instruction of both processors must be same.

102. (A) Assemblers provide macro facilties also.

103. (B)

104. (C)

105. (B) Active hub is part of CPU which actively participates in various operation of controlling in

CPU

106. (B) Micro program is set of instructions and other method is hardwired control system.

107. (C)

108. (C)

109. (C)

110. (A)

111. (D)

112. (B)

113. (C)

114. (A)

115. (B)

116. (B)

117. (B)

118. (B)

119. (B)

120. (D)

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