RCDD TEST QUESTIONS (TOPIC 1 - TOPIC 7) WITH
COMPLETE SOLUTIONS.
If the input signal power to a communication system is 1 W and the output power
is 1 mW, the system attenuation is:
A. 3 dB
B. 20 dB
C. 30 dB
D. 40 dB
E. 1000 dB
C. 30 dB
The signal at the input to a balanced twisted pair cable is 10 mW. The cable is
1000 feet long and has an attenuation of 1 dB per 100 feet. This cable is
connected to the input of a receiver. The noise level at the input to the receiver is
1 microwatt. What is the signal-to- noise ratio (SNR) (dB) at the receiver input?
A. 10 dB
B. 30 dB
C. 40 dB
D. 60 dB
E. 100 dB
B. 30 dB
A SONET OC-1 channel can carry 672 voice signals and has a data rate of 51.84
Mbps. ASONET OC-48 channel can carry 32,256 voice channels. What MINIMUM
data rate is required for the OC-48 channel?
A. 155 Mbps
B. 622 Mbps
C. 2.5 Gbps
D. 5 Gbps
E. 10 Gbps
C. 2.5 Gbps
All of the following are nominal wavelengths for laser light sources EXCEPT:
A. 700 nm
B. 850 nm
C. 1300 nm
D. 1310 nm
E. 1550 nm
A. 700 nm
A video camera has a coaxial cable output. The video signal is to be distributed to
devices that have balanced twisted pair inputs. The transition between these two
different transmission media can be accomplished by using a:
,A. Balun
B. Converter
C. Modulator
D. Cross connect
E. Transceiver
A. Balun
The public telephone system is an example of a __________ system.
A. Simplex
B. Half-duplex
C. Full-duplex
D. Purely analog
E. Purely digital
C. Full-duplex
Wave division multiplexing (WDM) is most similar to:
A. Amplitude modulation
B. Frequency modulation
C. Time division multiplexing
D. Frequency division multiplexing
E. Carrier sense multiple access with collision detection (CSMA/CD)
D. Frequency division multiplexing
You must place CAT6 cable above a factory floor with automated welding
machines and hammer forges. Of the following, what type of shielding would be
most effective?
A. Multi-layer braid
B. Foil and braid
C. Solid metallic conduit
D. Flex metallic conduit
E. Sch. 40 PVC conduit
C. Solid metallic conduit
You must place a cable between 2 equipment locations with separate grounds
having a potential difference between them of 2.1 V rms. Which one of the
following cables should NOT be used?
A. Multimode
B. Singlemode
C. UTP
D. STP
D. STP
Two sinusoidal signals have the same amplitude (A) and the same frequency (f).
They differ in phase by 180 degrees. If these two signals are added together, the
result is a sinusoidal signal having an amplitude of:
A. Zero
, B. 0.707A and a frequency of f
C. A and a frequency of 2f
D. 2A and a frequency of f
E. 2A and a frequency of 2f
A. Zero
Composite conductors, although not generally recommended, may be used in
special circumstances because they provide all of the following advantages
EXCEPT:
A. Have good digital transmission characteristics
B. Lightweight
C. Inexpensive
D. Easy to produce
E. Easily embedded into other materials
A. Have good digital transmission characteristics
Which is an advantage of stranded conductors over solid conductors?
A. Less costly
B. Simpler terminations
C. Better high frequency performance
D. More flexible
D. More flexible
The conversion of an analog speech signal to a pulse code modulation (PCM)
digital signal involves all of the following steps EXCEPT:
A. Low pass filtering
B. Periodic sampling
C. Quantizing
D. Companding
E. Amplitude modulation
E. Amplitude modulation
Assume that the optical power transmitted by a 62.5/125 multimode fiber is
distributed uniformly across its core. If this fiber is perfectly coupled (i.e., the two
fibers are aligned and abutted) to a 50/125 fiber, what is the percent of power that
is lost?
A. 0 percent
B. 36 percent
C. 50 percent
D. 80 percent
E. 100 percent
B. 36 percent
Which of the following correctly lists the lowest frequency band to the highest
frequency band?
A. MF, HF, VHF, UHF
COMPLETE SOLUTIONS.
If the input signal power to a communication system is 1 W and the output power
is 1 mW, the system attenuation is:
A. 3 dB
B. 20 dB
C. 30 dB
D. 40 dB
E. 1000 dB
C. 30 dB
The signal at the input to a balanced twisted pair cable is 10 mW. The cable is
1000 feet long and has an attenuation of 1 dB per 100 feet. This cable is
connected to the input of a receiver. The noise level at the input to the receiver is
1 microwatt. What is the signal-to- noise ratio (SNR) (dB) at the receiver input?
A. 10 dB
B. 30 dB
C. 40 dB
D. 60 dB
E. 100 dB
B. 30 dB
A SONET OC-1 channel can carry 672 voice signals and has a data rate of 51.84
Mbps. ASONET OC-48 channel can carry 32,256 voice channels. What MINIMUM
data rate is required for the OC-48 channel?
A. 155 Mbps
B. 622 Mbps
C. 2.5 Gbps
D. 5 Gbps
E. 10 Gbps
C. 2.5 Gbps
All of the following are nominal wavelengths for laser light sources EXCEPT:
A. 700 nm
B. 850 nm
C. 1300 nm
D. 1310 nm
E. 1550 nm
A. 700 nm
A video camera has a coaxial cable output. The video signal is to be distributed to
devices that have balanced twisted pair inputs. The transition between these two
different transmission media can be accomplished by using a:
,A. Balun
B. Converter
C. Modulator
D. Cross connect
E. Transceiver
A. Balun
The public telephone system is an example of a __________ system.
A. Simplex
B. Half-duplex
C. Full-duplex
D. Purely analog
E. Purely digital
C. Full-duplex
Wave division multiplexing (WDM) is most similar to:
A. Amplitude modulation
B. Frequency modulation
C. Time division multiplexing
D. Frequency division multiplexing
E. Carrier sense multiple access with collision detection (CSMA/CD)
D. Frequency division multiplexing
You must place CAT6 cable above a factory floor with automated welding
machines and hammer forges. Of the following, what type of shielding would be
most effective?
A. Multi-layer braid
B. Foil and braid
C. Solid metallic conduit
D. Flex metallic conduit
E. Sch. 40 PVC conduit
C. Solid metallic conduit
You must place a cable between 2 equipment locations with separate grounds
having a potential difference between them of 2.1 V rms. Which one of the
following cables should NOT be used?
A. Multimode
B. Singlemode
C. UTP
D. STP
D. STP
Two sinusoidal signals have the same amplitude (A) and the same frequency (f).
They differ in phase by 180 degrees. If these two signals are added together, the
result is a sinusoidal signal having an amplitude of:
A. Zero
, B. 0.707A and a frequency of f
C. A and a frequency of 2f
D. 2A and a frequency of f
E. 2A and a frequency of 2f
A. Zero
Composite conductors, although not generally recommended, may be used in
special circumstances because they provide all of the following advantages
EXCEPT:
A. Have good digital transmission characteristics
B. Lightweight
C. Inexpensive
D. Easy to produce
E. Easily embedded into other materials
A. Have good digital transmission characteristics
Which is an advantage of stranded conductors over solid conductors?
A. Less costly
B. Simpler terminations
C. Better high frequency performance
D. More flexible
D. More flexible
The conversion of an analog speech signal to a pulse code modulation (PCM)
digital signal involves all of the following steps EXCEPT:
A. Low pass filtering
B. Periodic sampling
C. Quantizing
D. Companding
E. Amplitude modulation
E. Amplitude modulation
Assume that the optical power transmitted by a 62.5/125 multimode fiber is
distributed uniformly across its core. If this fiber is perfectly coupled (i.e., the two
fibers are aligned and abutted) to a 50/125 fiber, what is the percent of power that
is lost?
A. 0 percent
B. 36 percent
C. 50 percent
D. 80 percent
E. 100 percent
B. 36 percent
Which of the following correctly lists the lowest frequency band to the highest
frequency band?
A. MF, HF, VHF, UHF
