1. In a BJT amplifier with the introduction of feedback, the input impedance is reduced, output impedance is increased, bandwidth is increased but distortion reduced. The feedback type is

Voltage series

Current series

Voltage shunt

Current shunt

2. In a bipolar transistor biased in the forward active region, the base current is ib 50 µA and collector current is ic 2.7 mA. The value of a is

0.949

54

0.982

0.018

3. Which of the following power amplifiers has maximum efficiency and less distortion

Class A

Class B

Class AB

Class C

4. In phase-shift oscillator, a single RC network introduces a phase change of

360°

180°

90°

60°

5. If the input of ideal comparator shown in Fig. is a sinusoidal signal is 8 V (peak to peak) without any dc component, the output of the comparator has a duty cycle of

<img src='./qimages/3399-5.jpg'>

12

13

16

112

6. When a pnp transistor is operating in active region, the current in n region is due to

only holes

only electrons

mainly holes

mainly electrons

7. A bootstrap generally incorporates

CB configuration

CE configuration

Emitter follower

None of these

8. The voltage across load resistor of a capacitor coupled CE amplifier is

DC AC

DC only

AC only

Neither DC nor AC

9. Positive feedback is the same as

Frequency synthesis

Negative feedback

Degeneration

Regeneration

10. In the saturation region, the JFET transfer characteristics are

exponential

linear

parabolic

hyperbolic

11. The circuit shown in figure can be used as image description


<img src='./qimages/3399-11.jpg'>
Rectifier

Voltage to frequency converter

frequency to voltage converter

logarithmic amplifier

12. Find output voltage Vo in the circuit below image description
<img src='./qimages/3399-12.jpg'>
-1.1 V

1.1 V

1.0 V

10 V

13. Indicate which of the following pulse modulation system is analog

PCM

Differential PCM

PWM

Delta

14. An envelop detector is a

synchronous detector

asynchronous detector

product detector

coherent detector

15. On increasing quantization level in PCM, S/N ratio

increases

decreases

remains same

none of these

16. The IF stage of a super-heterodyne receiver employs

impedance coupling

capacitive coupling

double tuned transformer coupling

Single tuned transformer coupling

17. The phase velocity in a transmission line is

1/LC

route LC

LC

1/routeLC

18. The velocity of electromagnetic waves in free space is

<img src='./qimages/3399-18.jpg'>
19. VSWR is defined as the ratio

Vmin/Vmax

Vmax/Vmin

Vmax Vmin/Vmax Vmin

V max . V min

20. Poission's equation is given by


<img src='./qimages/3399-20.jpg'>

21. Which antenna is used in mobile handsets

Dish

Microstrip

Yagi

None of above

22. Which of the following is not classified as a photoconductive device

PIN photo diode

A photo transistor

A light dependent register

A photo voltaic cell

23. The lowest frequency used in satellite communication is

0.8 GHz

3 GHz

18 GHz

30 GHz

24. For global communication, minimum number of satellite used is

5

3

1

10

25. Copper-network can be converted to fibre optics by using

fibre hubs

media converters

patch panel

rewiring

26. Dispersion in an optical fibre used in a communication link is of which type

Angular Dispersion

Modal Dispersion

Chromatic Dispersion

Dispersion arising due to structural irregularities in the fibre

27. Insertion of a record in a linked list involves the modification of

4 pointer

3 pointer

2 pointer

1 pointer

28. The first machine cycle of an instruction is always

a memory read cycle

a fetch cycle

an I/O read cycle

a memory write cycle

29. Accumulator content in 8085 are A 4H and CY 0. Accumulator content after executing RLC two times will be

92 H

49 H

48 H

91 H

30. What would be the equivalent of A3C5H hexadecimal number is binary form

1010 0011 1100 1010

1010 0011 1100 1100

1100 1011 0011 1101

1010 0011 1100 0101

31. In RAM chip with a total of 8096 words, the word addresses ranges from

1 to 8096

0 to 8095

1 to 8095

0 to 8096

32. Which of the following is not a basic element within the microprocessor

Micro controller

Arithmetic Logic Unit

Temporary register

Accumulator

33. MOV AL, OFAH is an example of

Immediate Addressing Mode

Direct Addressing Mode

Register Indirect Addressing Mode

Register Addressing Mode

34. The Medium Scale Integration has

more than 100 transistor

less than 100 transistor

less than 10 transistor

more than 1000 transistor

35. Which of following devices are VLSI

Microprocessor Pentium-4

SL 100 BJT

Wave guide

Optical fibre

36. Carbon is in the group IV of periodic table, even then, it is not used as semiconductor because it has

high dielectric constant

large energy gap 5 eV)

low temperature coefficient

low thermal conductivity

37. For a super conductor, the relative permeability is

zero

high

low

either low or high

38. In a semiconductor, holes exists in band.

the conduction band

the forbidden energy

no

the valence band

39. The binary equivalent of the decimal number 78 is

1001110

111001

1000111

110011

40. A

AB C

AB AC

A



41. In combinational logic circuit shown in figure has an output image description


<img src='./qimages/3399-41.jpg'>

ABC

A . B . C

A B C

A B C

42. A counter has N flip flops, the total number of states are

N

2N

3N

4N

43. The counter in figure is image description


<img src='./qimages/3399-43.jpg'>
mod 3

mod 6

mod 8

mod 7

44. The equivalent resistance RAB in the circuit is image description

<img src='./qimages/3399-44.jpg'>


45. Consider the following circuit image description find current I in the above circuit.

<img src='./qimages/3399-45.jpg'>
0 A

2 A

5 A

6 A

46. Consider signal M cos 4piet) cos (2pie × 103t), it contains the frequency components (in Hz)

998, 1000 and 1002

1000 and 2000

dc 2 and 1000

………., 996, 998, 1000, 1002, 1004 …

47. Which one of the following is a passive transducer

Piezoelectric

Thermocouple

Photovoltaic cell

LVDT

48. LVDT is used to measure

Displacement

Pressure

Temperature

None of above

49. Superposition theorem is not applicable for

Voltage calculation

Current calculation

Power calculation

Passive element

50. The energy stored in an electric field is given by

<img src='./qimages/3399-50.jpg'>


51. Maxwell's equation for EM waves can be applied to

Dielectric medium
Conductive medium
Plasma
Free space

Select the correct choice

only

only

only

All above

52. The dominant mode in a circular waveguide is

TEM mode

TM01 mode

TE21 mode

TE11 mode

53. In parametric amplifier used in microwave communication systems, the gain is mainly restricted by

Ambient temperature

Pump frequency

Pump bandwidth

Pump energy

54. A 3-port circulator is shown in figure, its scattering matrix is image description
<img src='./qimages/3399-54.jpg'>

55. Main advantage of TWT over Klystron is

higher Bandwidth

higher gain

higher frequency

higher output

56. In a CRO by changing time-base circuit, we change

amplitude of sawtooth voltage

frequency of sawtooth voltage

Gain of waveform

frequency of vertical amplitude

57. The closed-loop-gain of the system shown in Fig. image description

<img src='./qimages/3399-57.jpg'>


6

6

2

58. Laplace transform of the given signal u(t is

e-2s/s

1/s



e-s

59. Z and Laplace transform are related by

s In Z

s lnZ/T

s Z

s T/In Z

60. Fourier transform of unit step function is

<img src='./qimages/3399-60.jpg'>
61. of the varactor-diode changes with the change in applied voltage.

Resistance

Reactance

Concentration of carrier

Temperature

62. Tropospheric scatter is used with frequencies in the following range

HF

VHF

UHF

VLF

63. Performance of which one of the following diodes is not based on its negative resistance

GUNN

IMPATT

TUNNEL

BACKWARD

64. A wave guide can be considered to be a

low pass filter

high pass filter

band pass filter

band reject filter

65. The main disadvantage of the two-hole directional coupler is

low directional coupling

poor directivity

high SWR

narrow bandwidth

66. The UHF frequency range propagates by means of

sky wave

surface wave

space wave

None of the above

67. In TV 4 3 represents the

interlace ratio

maximum horizontal deflection

aspect ratio

ratio of the two diagonals

68. A solution to the blind speed problem is to

change the doppler frequency

vary the PRF

use monopulse

use MTI

69. A CW radar can not give information about

Range

Direction

Velocity

All of the above

70. The word LORAN means

Long Range Navigator

Long Range TV Transmission

Long Range Cable Transmission

Either