# MCQ in Transmission Fundamentals Part 2 | ECE Board Exam

(Last Updated On: May 6, 2020) This is the Multiples Choice Questions Part 2 of the Series in Transmission Fundamentals as one of the Communications Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies, Communications Books, Journals and other Communications References.

#### MCQ Topic Outline included in ECE Board Exam Syllabi

• MCQ in Transmission System
• MCQ in Transmission Medium
• MCQ in Velocity and Line Wavelength
• MCQ in Characteristics Impedance
• MCQ in Primary Line Constants and Propagation Constants
• MCQ in Standing Waves
• MCQ in Voltage Standing Wave Ratio
• MCQ in Telephone Lines and Cables
• MCQ in Wave Guides
• MCQ in Balanced and Unbalanced Lines
• MCQ in Twisted pair wire, Coaxial Cable
• MCQ in Decibel
• MCQ in Signal and Noise Fundamentals

#### Continue Practice Exam Test Questions Part 2 of the Series

51. If the grade of service of a telephone system indicated P = 0.05, what does it mean?

a. Completed calls of 5%

b. Lost calls of 5%

c. Lost calls of 95%

d. Lost calls of 105%

Solution:

52. ________ is the Out-of-Band signaling between Toll Central Offices (Bell System Standard).

a. 3, 825 Hz

b. 3, 700 Hz

c. 2, 600 Hz

d. 800 Hz

Solution:

53. In a telephone system, the customer’s telephone directory numbering is from 000 to 999, what is the capacity of a telephone system numbering from 000 to 999?

a. 100 lines

b. 1000 lines

c. 10, 000 lines

d. 100, 000 lines

Solution:

54. If the SWR is infinite, what type of load transmission line has?

a. Purely reactive

b. Purely resistive

c. Purely capacitive

d. Purely inductive

Solution:

55. Not more than _______ digits make up an international telephone number as recommended by CCITT REC. E. 161.

a. 8

b. 10

c. 11

d. 12

Solution:

56. One (1) Erlang is equal to _______.

a. 360 CCS

b. 36 CCS

c. 3.6 CCS

d. 100 CCS

Solution:

57. Standard tariff for flat rate telephone service beyond the normal flat rate in that area.

a. WATS

b. OTLP

c. TIP

d. DTWX

Solution:

58. The standard analog telephone channel bandwidth.

a. 300 – 3400 Hz

b. 1200 Hz

c. 200 – 3200 Hz

d. 300 – 3000 Hz

Solution:

59. Type of switching in which a pair of wire from the telephone set terminates in a jack and the switch is supervised by an operator.

a. Crossbar switching

b. Manual switching

c. Electronic switching

d. Step-by-step switching

Solution:

60. Every time when the telephone is idle, the handset is in the _______ state.

a. On-hook

b. Off-hook

c. Busy

d. Spare

Solution:

61. _______ is a component in the telephone set that has the primary function of compensating for the local loop length.

a. Resistor

b. Varistor

c. Capacitor

d. Induction coil

Solution:

62. What kind of receiver is used in conventional telephone handset?

a. Carbon

b. Electromagnetic

c. Ceramic

d. Capacitor

Solution:

63. A voice-grade circuit using the PTN ha an ideal passband of

a. 0 to 4 Hz

b. 0 to 4 MHz

c. 0 to 4 kHz

d. 0 to 4 GHz

Solution:

64. ________ is the minimum-quality circuit available using the PTN.

b. Basic voice channel (VC)

c. Basic voice band (VB)

d. Basic telephone channel

Solution:

65. Direct distance dialing (DDD) network is called

a. Private-line network

b. PT network

c. Dial-up network

d. Trunk network

Solution:

66. What is the advantage of sidetone?

a. Transmission efficiency is increased

b. Speaker increases his voice resulting in a strengthened signal

c. No dissipation of energy in the balancing network

d. Assure the customer that the telephone is working

Solution:

67. ________ is a special service circuit connecting two private branch exchanges (PBX).

a. Phantom line

b. Tie trunk

c. Tandem trunk

d. Private line

Solution:

68. The published rates, regulation, and descriptions governing the provision of communications service for public use.

a. Toll rate

b. Tariff

c. Bulk billing

d. Detailed billing

Solution:

69. What is the power loss of a telephone hybrid?

a. 1 dB

b. 2 dB

c. 3 dB

d. 6 dB

Solution:

70. Telephone channel has a band-pass characteristic occupying the frequency range of _______.

a. 300 – 400 Hz

b. 300 – 3400 Hz

c. 300 – 3000 Hz

d. 300 – 2700 Hz

Solution:

71. The first Strowger step-by-step switch was used in _______.

a. 1875

b. 1890

c. 1897

d. 1913

Solution:

72. What is the phase delay of an 800 Hz voice signal if the phase shift is 15 degrees?

a. 52 μsec

b. 1.25 μsec

c. 83.33 μsec

d. 26 μsec

Solution:

73. What is the CCITT recommendation for a preparation of loss plan, a variable loss plans and a fixed loss plan?

a. G.133

b. G.141

c. G.132

d. G.122

Solution:

74. What is the diameter of a copper wire to be used in a 16 km loop with a dc loop resistance of 100 ohms/km?

a. 0.838 mm

b. 0.465 mm

c. 1.626 mm

d. 2.159 mm

Solution:

75. What kind of cell is appropriate for load management, fast moving mobiles and low-usage areas?

a. Pico cells

b. Micro cells

c. Nano cells

d. Umbrella cells

Solution:

76. In cellular networks, standard base station antennas are placed by _______.

b. flat plate antenna

c. dipole array

d. focused antenna

Solution:

77. What is the basis of the first generation wireless local loop?

a. Digital cellular technology

b. Analogue cellular technology

c. PSTN

d. AMPS technology

Solution:

78. When the calling party hears a “busy” tone on his telephone, the call is considered

a. lost

b. disconnected

c. completed

d. incomplete

Solution:

79. Short-circuited stubs are preferred to open circuited stubs because the latter are

a. more difficult to make and connect

b. made of a transmission line with a different characteristic impedance

d. incapable of giving a full range of reactances

Solution:

80. What is the ratio of the reflected voltage to the incident voltage?

a. VSWR

b. ISWR

c. SWR

d. Coefficient of reflection

Solution:

81. One method of determining antenna impedance.

a. Sub matching

b. Trial and error

c. Smith chart

d. Quarter-wave matching

Solution:

82. ________ is a single conductor running from the transmitter to the antenna.

a. Single-wire line

b. Microstrip

d. Coaxial line

Solution:

83. Coaxial cable impedance is typically _______.

a. 150 to 300 ohms

b. 50 to 75 ohms

c. 30 to 45 ohms

d. 300 to 600 ohms

Solution:

84. Waveguide becomes compulsory above what frequencies?

a. Above 3 GHz

b. Above 10 kHz

c. At 300 MHz

d. Above 10 GHz

Solution:

85. Nominal voice channel bandwidth is _______.

a. 20 to 30 kHz

b. 0 to 3 kHz

c. 4 kHz

d. 55 kHz above

Solution:

86. Echo suppressors are used on all communications system when the round trip propagation time exceeds _______.

a. 50 ms

b. 30 ms

c. 100 ms

d. 1 ms

Solution:

87. A radio transmission line of 300 ohms impedance is to be connected to an antenna having an input impedance of 150 ohms. What is the impedance of a quarter-wave matching line?

a. 212 ohms

b. 250 ohms

c. 200 ohms

d. 150 ohms

Solution:

88. Quarter-wavelength line is used as _______.

a. impedance transformer

b. lecher line

c. transmission line

d. harmonic suppressor

Solution:

89. The transmission lines which can convey electromagnetic waves only in higher modes is usually called

a. coaxial cable

b. waveguide

c. power lines

d. twisted wire of telephone line

Solution:

90. Why is nitrogen gas sometimes used in waveguide?

a. To increase the distributed capacitance

b. To keep the waveguide dry

c. To reduce the skin effect at the walls of the guide

d. To raise the guide’s wave impedance

Solution:

91. The apparent speed of propagation along a waveguide based on the distance between wavefronts along the walls of the guide is called

a. group velocity

b. phase velocity

c. normal velocity

d. abnormal velocity

Solution:

92. How do you couple in and out of a waveguide?

a. Wrap a coil of wire around one end of the waveguide

b. Insertion of an E-probe into the waveguide

c. Insertion of an H-loop into the waveguide

d. Both B and C

Solution:

93. A rectangular waveguide is operating in the dominant TE10 mode. The associated flux lines are established

a. transversely across the narrow dimension of the waveguide

b. transversely across the wide dimension of the waveguide

c. in the metal walls parallel to the direction of propagation

d. in the metal walls perpendicular to the direction of propagation

Solution:

94. For dominant mode of a rectangular waveguide, the distance between two instantaneous consecutive positions of maximum field intensity (in a direction parallel to the walls of the waveguide) is referred to as half of the

a. free-space wavelength

b. cutoff wavelength in the wide dimension

c. guide wavelength

d. group wavelength

Solution:

95. The guide wavelength, in a rectangular waveguide is

a. equal to the free-space wavelength at the cutoff frequency

b. equal to the free-space wavelength for the same signal frequency

c. less than the free-space wavelength at the cut-off frequency

d. greater than the free-space wavelength at the same signal frequency

Solution:

96. Using the TE10 mode, microwave power can only be transmitted in free rectangular guide provided

a. the wider dimension is less than one-half of the wavelength in free space

b. the narrow dimension is less than one-quarter of the wavelength in free space

c. the wide dimension is greater than one-half of the guide wavelength

d. the wide dimension is greater than one-half of the wavelength in free space

Solution:

97. If the signal frequency applied to a rectangular guide is increased and the dominant mode is employed

a. the free space wavelength is increased

b. the phase velocity increased

c. the guide wavelength is increased

d. the group velocity, Vg, is increased

Solution:

98. If a 6 GHz signal is applied to a rectangular waveguide and the reflection angle is 20o, what is the value of the guide wavelength?

a. 6.10 cm

b. 5.32 cm

c. 4.78 cm

d. 5.00 cm

Solution:

99. The inner dimensions of a rectangular wavelength are 1.75 cm by 3.5 cm. The cutoff wavelength for the dominant mode is

a. 1.75 cm

b. 3.5 cm

c. 7.0 cm

d. 0.4375 cm

Solution:

100. A signal whose wavelength is 3.5 cm is being propagated along a guide whose inner dimensions are 2 cm by 4 cm. What is the value of the guide wavelength?

a. 3.12 cm

b. 3.89 cm

c. 3.57 cm

d. 6.30 cm

Solution:

#### Questions and Answers in Transmission Fundamentals Series

Following is the list of multiple choice questions in this brand new series:

MCQ in Transmission Fundamentals
PART 1: MCQ from Number 1 – 50                        Answer key: PART 1
PART 2: MCQ from Number 51 – 100                   Answer key: PART 2
PART 3: MCQ from Number 101 – 150                 Answer key: PART 3
PART 4: MCQ from Number 151 – 200                 Answer key: PART 4
PART 5: MCQ from Number 201 – 250                 Answer key: PART 5
PART 6: MCQ from Number 251 – 300                 Answer key: PART 6
PART 7: MCQ from Number 301 – 350                 Answer key: PART 7
PART 8: MCQ from Number 351 – 400                 Answer key: PART 8
PART 9: MCQ from Number 401 – 450                 Answer key: PART 9
PART 10: MCQ from Number 451 – 500                Answer key: PART 10

### Complete List of MCQ in Communications Engineering per topic

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