RCDD UPDATED SCRIPT 2026 PRACTICE
SOLUTIONS GRADED A+
● B. Answer: 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
● C. Answer: 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
,● A. Answer: 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. Answer: 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
● C. Answer: The public telephone system is an example of a
__________ system.
A. Simplex
B. Half-duplex
,C. Full-duplex
D. Purely analog
E. Purely digital
● D. Answer: 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)
● C. Answer: 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
● D. Answer: 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 shouldNOT be used?
, A. Multimode
B. Singlemode
C. UTP
D. STP
● A. Answer: 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. Answer: 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
SOLUTIONS GRADED A+
● B. Answer: 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
● C. Answer: 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
,● A. Answer: 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. Answer: 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
● C. Answer: The public telephone system is an example of a
__________ system.
A. Simplex
B. Half-duplex
,C. Full-duplex
D. Purely analog
E. Purely digital
● D. Answer: 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)
● C. Answer: 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
● D. Answer: 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 shouldNOT be used?
, A. Multimode
B. Singlemode
C. UTP
D. STP
● A. Answer: 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. Answer: 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
