100 Top Telecom Multiple Choice Questions and Answers

Telecom Multiple Choice Questions:-

1. The numerical aperture value of a 62.5/125 ┬Ám multimode optical fiber is approximate:
a)0.10
b)0.20
c)0.275
d)0.375
Ans: c

2. The ability to transmit signals in either direction, but in only one direction at a time is referred to as ______transmission.
a)Half-duplex
b)Simplex
c)Dual-duplex
d)Full-duplex
Ans: a

3. Which one of the following statements about modal bandwidth is incorrect?
a)Manufacturers and suppliers typically refer to it as the optical fiber bandwidth
b)It is commonly expressed as a frequency-distance product
c)It is not a major consideration for link lengths of several hundred meters/feet or less
d)Is expressed as km/MHz
Ans: d

4. Which one of the following is not an acceptable characteristic of a transmission circuit?
a)High NEXT
b)Low SNR
c)High noise immunity
d)Low insertion loss/attenuation
Ans: b

5.The average splice loss for a single mode mechanical splice is:
a)0.05 dB
b)0.10 dB
c)0.30 dB
d)0.75 dB
Ans: b

6. Telecommunications transmission circuits are generally classified as:
a)Half-duplex,full-duplex, and dual-duplex
b)Simplex, half-duplex, and dual-duplex
c) Simplex, half-duplex, and full-duplex
d) Simplex, full-duplex, and dual-duplex
Ans: c

7. The three most commonly used wavelength windows for optical communications are near:
a)780 nm,850 nm,and 1300 nm
b) 780 nm, 850 nm, and 1550 nm
c) 780 nm, 1300 nm, and 1550 nm
d) 850 nm, 1300 nm, and 1550 nm
Ans: d

8.A rating of 50 dB indicates a cable shield effectiveness that is considered to be:
a)Poor
b)Fair
c)Good
d)Excellent
Ans: c

9.For balanced twisted-pair cabling, bandwidth can be expressed as the frequency range where:
a)PSACR > 0
b) PSACR < 0
c) PSACR = 0
d)There is no relationship between bandwidth and PSACR
Ans: a

10.Short wavelength lasers are primarily used with:
a)Multimode optical fiber systems at the higher data rates
b) Multimode optical fiber systems at the lower data rates
c)Singlemode optical fiber systems at the higher data rates
d) Singlemode optical fiber systems at the lower data rates
Ans: a

11. The rate at which an optical fiber transmission changes in intensity is known as the ____ of the transmitter.
a)Center wavelength
b)Launch window
c)Power
d)Modulation frequency
Ans: d

12.A rating of 35 dB indicates a cable shield effectiveness that is considered to be :
a)Poor
b)Fair
c)Good
d)Excellent
Ans: b

13. To implement an IP telephony solution:
a)A separate line can be used to connect the IP telephone
b) A wireless connection using access points can be used to connect the IP telephone
c)The IP telephone can share the same line with the PC
d)All of the above
Ans: d

14.Which one of the following uses 4B5B/MLT-3 coding?
a)10BASE-T
b) 100BASE-TX
c) 100BASE-T4
d) 1000BASE-T
Ans: b

15. Typically, glass optical fibers have minimal chromatic dispersion characteristics at a center wavelength near:
a)780 nm
b)850 nm
c)1300 nm
d)1550 nm
Ans: c

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16. Capacitance is measured in units known as:
a)Decibels
b)Hertz
c)Henries
d)Farads
Ans: d

17.An analog signal that contains all the components necessary to construct a monochrome or color picture but has no audio information, is the definition of:
a)Composite video format
b)Broadband video format
c)Component video format
d)Baseband Video format
Ans: a

18. The average splice loss for a multimode fusion splice is:
a)0.05 dB
b)0.10 dB
c)0.30 dB
d)0.75 dB
Ans: a

19. For an optical fiber system, the essential determinants of end-to-end bandwidth are:
a)The optical fiber and the receiver
b)The transmitter and the optical fiber
c)The transmitter and the receiver
d)None of the above
Ans: b

20. How many balanced twisted-pairs are required for 1000BASE-T?
a)1
b)2
c)3
d)4
Ans: d

21. Delay skies is the difference in:
a)Propagation delay between conductors in the same pair
b)Propagation delay between pairs within the same cable sheath
c)Propagation velocity between conductors in the same pair
d)Propagation velocity between pairs within the same cable sheath
Ans: b

22. Analog transmission of voice information uses which frequency range?
a)30 Hz to 3100 Hz
b) 30 Hz to 3400 Hz
c) 300 Hz to 3100 Hz
d) 300 Hz to 3400 Hz
Ans: d

23. Increasing the length of an optical fiber link can result in:
a)Signal distortion
b)An increase in total signal attenuation
c)Reduced system bandwidth
d)All of the above
Ans: d

24. Baseband composite video signaling can be supported over a minimum of ____balanced twisted-pair cable in excess of 100 m(328 ft).
a)Category 3
b) Category 5
c) Category 5e
d) Category 6
Ans: a

25. Optical fibers have bandwidth limitations because of:
a)Insertion loss
b)Dispersion
c)Receiver limitations
d)Transmitter limitations
Ans: b

26. At voice frequencies, the principle elements contributing to loss and phase distortion are:
a)Return loss and mutual capacitance of a cable pair
b)Conductor resistance and inductance of a cable pair
c)Conductor resistance and mutual capacitance of a cable pair
d) Return loss and inductance of a cable pair
Ans: c

27. The _______is the maximum allowable loss for the end-to-end optical fiber cable system.
a)link loss budget
b)Power penalty
c)System Gain
d)None of the above
Ans: a

28.To faithfully reproduce an analog signal when it is converted from analog to digital and then back to analog, the sampling rate must be at least:
a)Twice the highest frequency component of the analog signal
b) Half the highest frequency component of the analog signal
c) Twice the lowest frequency component of the analog signal
d) Half the lowest frequency component of the analog signal
Ans: a

29. Decibel levels are used to express power ratios of :
a)Analog signals, regardless of media type
b) Digital signals, regardless of media type
c) All types of analog and digital signals, regardless of media type
d) All types of analog and digital signals, dependent on the media type

30.The transmitter light source that is used almost exclusively in single mode optical fiber links is the:
a)Vertical cavity surface emitting laser (VCSEL)
b)The light-emitting diode (LED)
c)Short wavelength laser
d)Laser diode
Ans: d