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.
Online Questions and Answers Topic Outline
- MCQs in Transmission System
- MCQs in Transmission Medium
- MCQs in Velocity and Line Wavelength
- MCQs in Characteristics Impedance
- MCQs in Primary Line Constants and Propagation Constants
- MCQs in Standing Waves
- MCQs in Voltage Standing Wave Ratio
- MCQs in Telephone Lines and Cables
- MCQs in Wave Guides
- MCQs in Balanced and Unbalanced Lines
- MCQs in Twisted pair wire, Coaxial Cable
- MCQs in Decibel
- MCQs in Signal and Noise Fundamentals
MCQs in Transmission Fundamentals Series
Following is the list of multiple choice questions in this brand new series:
Continue Practice Exam Test Questions Part II 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%
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
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
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
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
56. One (1) Erlang is equal to _______.
- a. 360 CCS
- b. 36 CCS
- c. 3.6 CCS
- d. 100 CCS
57. Standard tariff for flat rate telephone service beyond the normal flat rate in that area.
- a. WATS
- b. OTLP
- c. TIP
- d. DTWX
58. The standard analog telephone channel bandwidth.
- a. 300-3400 Hz
- b. 1200 Hz
- c. 200-3200 Hz
- d. 300-3000 Hz
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
60. Every time when the telephone is idle, the handset is in the _______ state.
- a. On-hook
- b. Off-hook
- c. Busy
- d. Spare
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
62. What kind of receiver is used in conventional telephone handset?
- a. Carbon
- b. Electromagnetic
- c. Ceramic
- d. Capacitor
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
64. ________ is the minimum-quality circuit available using the PTN.
- a. Basic voice grade (VG)
- b. Basic voice channel (VC)
- c. Basic voice band (VB)
- d. Basic telephone channel
65. Direct distance dialing (DDD) network is called
- a. Private-line network
- b. PT network
- c. Dial-up network
- d. Trunk network
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
67. ________ is a special service circuit connecting two private branch exchanges (PBX).
- a. Phantom line
- b. Tie trunk
- c. Tandem trunk
- d. Private line
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
69. What is the power loss of a telephone hybrid?
- a. 1 dB
- b. 2 dB
- c. 3 dB
- d. 6 dB
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
71. The first Strowger step-by-step switch was used in _______.
- a. 1875
- b. 1890
- c. 1897
- d. 1913
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
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
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
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
76. In cellular networks, standard base station antennas are placed by _______.
- a. adaptive array
- b. flat plate antenna
- c. dipole array
- d. focused antenna
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
78. When the calling party hears a “busy” tone on his telephone, the call is considered
- a. lost
- b. disconnected
- c. completed
- d. incomplete
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
- c. liable to radiate
- d. incapable of giving a full range of reactances
80. What is the ratio of the reflected voltage to the incident voltage?
- a. VSWR
- b. ISWR
- c. SWR
- d. Coefficient of reflection
81. One method of determining antenna impedance.
- a. Sub matching
- b. Trial and error
- c. Smith chart
- d. Quarter-wave matching
82. ________ is a single conductor running from the transmitter to the antenna.
- a. Single-wire line
- b. Microstrip
- c. Twin-lead
- d. Coaxial line
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
84. Waveguide becomes compulsory above what frequencies?
- a. Above 3 GHz
- b. Above 10 kHz
- c. At 300 MHz
- d. Above 10 GHz
85. Nominal voice channel bandwidth is _______.
- a. 20 to 30 kHz
- b. 0 to 3 kHz
- c. 4 kHz
- d. 55 kHz above
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
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
88. Quarter-wavelength line is used as _______.
- a. impedance transformer
- b. lecher line
- c. transmission line
- d. harmonic suppressor
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
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
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
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
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
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
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
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
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
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
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
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