ECE Transmission Fundamentals Q&A

1. What is the opposition to the transfer of energy which is consider the dominant
Characteristics of a cable or circuit that emanates from its physical structure?
A. Conductance
B. Resistance
C. Reactance
(D) Impedance
2. When load impedance equal to Zo of the line, it means that the load
____ all the power.
A. reflects
(B) absorbs
C. attenuates
D. radiates
3. Impedance matching radio of a coax balun.
A. 1:4
(B) 4:1
C. 2:1
D. 3:2
4. Which stands for dB relative level?
A. dBm
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. 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
8. Which indicate the relative energy loss in a capacitor?
A. Quality factor
B. Reactive factor
(C) Dissipation factor
D. Power factor
9. What is the standard test tone?
A. 0 dB
B. 0 dBW
(C) 0 dBm
D. 0 dBrn
10 The energy that neither radiated into space nor completely transmitted
A. Reflected waves
B. Captured waves
C. Incident waves
(D) Standing waves
11. 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
12. ____ is the transmission and reception of information
A. Modulation
(B) Communications
C. Radiation
D. Emission
13. What is the loss of the circuit in dB if the power ratio of output is 0.01?
(A) 20
B. -20
C. 40
D. -40
14. Transmission lines are either balanced or unbalanced with respect to
A. negative terminal
B. reference
(C) ground
D. positive terminal
15. 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
16. ___ is the advantage of the balanced transmission line compared to unbalance line.
(A) Low attenuation
B. Easy installation
C Low radiaton loss
D. Tensile strength
17 ____ is the method of determining the bandwidth of any processing system.
A. Fourier series
(B) Spectral analysis
C. Frequency analysis
D. Bandwidth analysis
18. 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 wall of the guide
D. Radiation loss
19. What device that converts a balanced line to an unbalanced line of a transmission line
A. Hybrid
B. Stub
C. Directional coupler
(D) Balun
20. What is the average power rating of RG-58 C/u?
A. 25 W
(B) 50 W
C. 75 W
D. 200 W
21. The velocity factor of the 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
22. One of the following is not a bounded media.
A. Coaxial line
B. Two-wire line
C. Waveguide
(D) Ocean
23. 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
24. The following are considered primary line constant except
A. conductance
B. resistance
C. capacitance
(D) complex propagation constant
25. The dielectric constants of materials commonly used in transmission line
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
26. The concept used to make one Smith chart universal is called
A. ionization
(B) normalization
C. rationalization
D. termination
27. What are the basic elements of communication system?
A). Source, transmission channel, transmitter
(B) Transmitter, receiver, transmission, channel
C. Information, transmission channel receiver
D. Sender and receiver
28. ____ is the transmission of printed material over telephone lines.
A) Internet
B) Data communication
C) Telegraphy
(D) Facsimile
29. ____ 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
30. If the SWR is infinite, what type of load transmission line has?
(A) Purely reactive
B. Purely resistive
C. Purely capacitive
D. Purely inductive