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:
Start Practice Exam Test Questions Part I of the Series
1. What is the opposition to the transfer of energy which is considered the dominant characteristic of a cable or circuit that emanates from its physical structure?
- a. Conductance
- b. Resistance
- c. Reactance
- d. Impedance
2. When load impedance equals to Zo of the line, it means that the load _____ all the power.
- a. reflects
- b. absorbs
- c. attenuates
- d. radiates
3. impedance matching ratio of a coax balun.
- a. 1:4
- b. 4:1
- c. 2:1
- d. 3:2
4. Which stands for dB relative level?
- a. dBrn
- b. dBa
- c. dBr
- d. dBx
5. Standard test tone used for audio measurement.
- a. 800 Hz
- b. 300 Hz
- c. 100 Hz
- d. 1000 Hz
6. When VSWR is equal to zero, this means
- a. that no power is applied
- b. that the load is purely resistive
- c. that the load is a pure reactance
- d. that the load is opened
7. _______ is the ratio of reflected voltage to the forward travelling voltage.
- a. SWR
- b. VSWR
- c. Reflection coefficient
- d. ISWR
8. Transmission line must be matched to the load to ______.
- a. transfer maximum voltage to the load
- b. transfer maximum power to the load
- c. reduce the load current
- d. transfer maximum current to the load
9. Which indicate the relative energy loss in a capacitor?
- a. Quality factor
- b. Reactive factor
- c. Dissipation factor
- d. Power factor
10. What is the standard test tone?
- a. 0 dB
- b. 0 dBW
- c. 0 dBm
- d. 0 dBrn
11. The energy that neither radiated into space nor completely transmitted.
- a. Reflected waves
- b. Captured waves
- c. Incident waves
- d. Standing waves
12. Micron is equal to _______ meter.
- a. 10-10
- b. 10-9
- c. 10-6
- d. 10-3
13. 1 Angstrom (A) is equal to _______.
- a. 10-3 micron
- b. 10-10 m
- c. 10-6 micron
- d. 10-6 m
14. Why is it impossible to use a waveguide at low radio frequencies?
- a. Because of the size of the waveguide
- b. Due to severe attenuation
- c. Due to too much radiation
- d. All of these
15. ________ is the transmission and reception of information.
- a. Modulation
- b. Communications
- c. Radiation
- d. Emission
16. What is the loss of the circuit in dB if the power ration of output to input is 0.01?
- a. 20
- b. -20
- c. 40
- d. -40
17. Transmission lines are either balanced or unbalanced with respect to
- a. Negative terminal
- b. Reference
- c. Ground
- d. Positive terminal
18. The standing wave ratio is equal to _______ if the load is properly matched with the transmission line.
- a. Infinity
- b. 0
- c. -1
- d. 1
19. ________ is the advantage of the balanced transmission line compared to unbalanced line.
- a. Low attenuation
- b. Easy installation
- c. Low radiation loss
- d. Tensile strength
20. _______ is the method of determining the bandwidth of any processing system.
- a. Fourier series
- b. Spectral analysis
- c. Frequency analysis
- d. Bandwidth analysis
21. What causes the attenuation present in a waveguide?
- a. The air dielectric filling the guide
- b. The coating of silver inside
- c. Losses in the conducting walls of the guide
- d. Radiation loss
22. A device that converts a balanced line to an unbalanced line of a transmission line.
- a. Hybrid
- b. Stub
- c. Directional coupler
- d. Balun
23. What is the approximate line impedance of a parallel-strip line spaced 1 cm apart with the length of 50 cm?
- a. 10 ohms
- b. 15 ohms
- c. 18 ohms
- d. 23 ohms
24. What is the average power rating of RG-58 C/u?
- a. 25 W
- b. 50 W
- c. 75 W
- d. 200 W
25. A coaxial cable used for high temperatures.
- a. RG-58C
- b. RG-11A
- c. RG-213
- d. RG-211
26. If you have available number of power amplifiers with a gain of 100 each, how many such amplifiers do you need to cascade to give an overall gain of 60dB?
- a. 2
- b. 3
- c. 4
- d. 5
27. You are measuring noise in a voice channel at a -4 dB test point level, the meter reads -73 dBm, convert the reading into dBrnCO.
- a. 12
- b. 16
- c. 18
- d. 21
28. The velocity factor for a transmission line
- a. depends on the dielectric constant of the material used
- b. increases the velocity along the transmission line
- c. is governed by the skin effect
- d. is higher for a solid dielectric than for air
29. Impedance inversion can be obtained by
- a. a short-circuited stub
- b. an open-circuited stub
- c. a quarter-wave line
- d. a half-wave line
30. Transmission lines when connected to antennas have
- a. capacitive load
- b. resistive load whose resistance is greater than the characteristic impedance of the line
- c. resistive load whose resistance is less than the characteristic impedance of the line
- d. resistive load at the resonant frequency
31. One of the following is not a bounded media.
- a. Coaxial line
- b. Two-wire line
- c. Waveguide
- d. Ocean
32. The impedance measured at the input of the transmission line when its length is infinite.
- a. Input impedance
- b. Open circuit impedance
- c. Characteristic impedance
- d. Short circuit impedance
33. The following are considered primary line constants except
- a. conductance
- b. resistance
- c. capacitance
- d. complex propagation constant
34. The dielectric constants of materials commonly used in transmission lines range from about
- a. 1.2 to 2.8
- b. 2.8 to 3.5
- c. 3.5 to 5.2
- d. 1.0 to 1.2
35. Typically, the velocity factor (VF) of the materials used in transmission lines range from
- a. 0.6 to 0.9
- b. 0.1 to 0.5
- c. 1.0 to 0.9
- d. 0.6 to 0.8
36. For an air dielectric two-wire line, the minimum characteristic impedance value is
- a. 85 ohms
- b. 85 ohms
- c. 90 ohms
- d. 88 ohms
37. When a quarter-wave section transmission line is terminated by a short circuit and is connected to an RF source at the other end, its input impedance is
- a. inductive
- b. capacitive
- c. resistive
- d. equivalent to a parallel resonant LC circuit
38. A transmitter operating at 30 MHz with 4 W output is connected via 10 m of RG-8A/u cable to an antenna that has an input resistance of 300 ohms. Find the reflection coefficient.
- a. 0.71
- b. 0.77
- c. 0.97
- d. 0.76
39. A quarter wave transformer is connected to a parallel wire line in order to match the line to a load of 1000 ohms. The transformer has a characteristic impedance of 316.23 ohms. The distance between centers is 4 inches. What is the percentage reduction in the diameter of the line?
- a. 85%
- b. 83%
- c. 86%
- d. 90%
40. The concept used to make one Smith chart universal is called
- a. ionization
- b. normalization
- c. rationalization
- d. termination
41. What are the basic elements of communications system?
- a. Source, transmission channel, transmitter
- b. Transmitter, receiver, transmission channel
- c. Information, transmission channel, receiver
- d. Sender and receiver
42. ________ is the transmission of printed material over telephone lines.
- a. Internet
- b. Data communication
- c. Telegraphy
- d. Facsimile
43. ________ is a continuous tone generated by the combination of two frequencies of 350 Hz and 440 Hz used in telephone sets.
- a. DC tone
- b. Ringing tone
- c. Dial tone
- d. Call waiting tone
44. ________ are unidirectional amplifiers having 20-25 decibel gain that are placed about 75 km apart used to compensate for losses along the telephone line.
- a. VF repeaters
- b. Loading coils
- c. Loop extenders
- d. Echo suppressors
45. ________ is a component in the telephone set that has the primary function of interfacing the handset to the local loop.
- a. Resistor
- b. Capacitor
- c. Varistor
- d. Induction coil
46. Pulse dialing has ________ rate.
- a. 20 pulses/min
- b. 10 pulses/min
- c. 10 pulses/sec
- d. 80 pulses/sec
47. ________ is a telephone wire that connects two central offices.
- a. 2-wire circuit
- b. Trunk line
- c. Leased line
- d. Private line
48. The central switching office coordinating element for all cell sites that has cellular processor and a cellular switch. It interfaces with telephone company zone offices, control call processing and handle billing activities.
- a. MTSO
- b. Cell site
- c. PTSN
- d. Trunk line
49. ________ in a cellular system performs radio-related functions for cellular site.
- a. Switching system
- b. Base station
- c. Operation and support system
- d. Mobile station
50. A technology used to increase the capacity of a mobile phone system.
- a. Frequency re-use
- b. Cell splitting
- c. TDM
- d. FDM
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