RCDD Registered Communications Distribution Designer

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Question 1

Time division multiplexing (TDM) systems are designed to transport ________ between
end point systems.

  • A. Only analog signals
  • B. Only digital signals
  • C. A mix of both analog and digital signals
  • D. Both analog and digital signals, but only one type at a time


Answer : B

Question 2

A reasonable approximation for the signal speed in 100 ohm balanced twisted pair cable is
__________, where c is the velocity of light in free space.

  • A. 0.2 c
  • B. 0.4 c
  • C. 0.6 c
  • D. 08 c
  • E. 0.9 c


Answer : C

Question 3

Which characteristic is an advantage of copper based media over optical fiber cable?

  • A. Weight
  • B. Corrosion resistance
  • C. Ability to handle analog signals
  • D. Susceptibility to EMI
  • E. Very high data rates


Answer : C

Question 4

Which electrical characteristic is displayed with the correct preferred value?

  • A. Dielectric constant – high value
  • B. Dielectric strength – high value
  • C. Dissipation factor – low value
  • D. Insulation resistance - high value


Answer : A

Question 5

Optical transmitters are typically one of the following types EXCEPT:
A. Light-emitting diode (LED)
B. Short wavelength laser compact disc (CD)
C. Vertical cavity surface emitting laser (VCEL)
D. Laser diode (LD)
E. Overfilled launch (OFL)



Answer : E Topic 2, Electromagnetic Compatibility

Question 6

You are placing Category 6 unshielded twisted-pair (UTP) in cable tray down a hallway
past the elevator mechanical room. What action should you take to avoid effects of
electromagnetic interference (EMI)?

  • A. Provide a minimum separation of 1194 mm (47 in)
  • B. Provide a minimum separation of 2060 mm (81 in)
  • C. Require the architect to install metallic foil shielding on the mechanical room walls
  • D. Provide RMC/IMC (rigid metallic conduit/intermediate metal conduit) through all areas within 4.6 m (15 ft) of the mechanical room


Answer : A

Question 7

You have discovered a common mode current on the metallic cable sheaths of your
building riser cables. What is the MOST likely cause for you to investigate?

  • A. Lack of cable protection
  • B. Two separate and distinct ground references
  • C. Improper secondary protection
  • D. Improper physical protection of cable
  • E. Improper placement and/or termination of cables


Answer : B

Question 8

What is the recommended MINIMUM separation of unshielded twisted-pair (UTP) cables
from fluorescent light fixtures?

  • A. 77 mm (3 in)
  • B. 30 mm (5.12 in)
  • C. 203 mm (8 in)
  • D. 324 mm (12.75 in)
  • E. 483 mm (19 in)


Answer : B

Question 9

You are required by architectural design to place UTP cables in the same space as
unshielded power lines. How should you proceed with the placement of your cables?

  • A. Require the architect/electrical engineer to place shielding in the space before your UTP is placed.
  • B. You should provide a minimum separation of 610 mm (24 in).
  • C. You should provide a minimum separation of 229 mm (9 in).
  • D. You should provide a minimum of two 101 mm (4 in) RMC.


Answer : B

Question 10

Which of the following is NOT a form of signal coupling between two (2) circuits?

  • A. Conductive
  • B. Inductive
  • C. Reactive
  • D. Capacitive
  • E. Electromagnetic


Answer : C

Question 11

A common mode (CM) signal can be converted to a differential mode (DM) signal as a
result of a(n):

  • A. Unbalanced circuit
  • B. Grounded circuit
  • C. Poorly timed signal
  • D. Improper dielectric material


Answer : A

Question 12

The electromagnetic spectrum of visible light lies in the ___________ frequency range of
the spectrum.

  • A. 1 GHz
  • B. 100 GHz
  • C. 10 THz
  • D. 1 PHz
  • E. 100 PHz


Answer : D

Question 13

The potential for ______ occurs when devices or systems share a common
electromagnetic environment and their operational frequencies overlap.

  • A. Electromagnetic interference (EMI)
  • B. (EMC)
  • C. Radio frequency interference (RFI)
  • D. Fast transients
  • E. Electrostatic discharge (ESD)


Answer : A

Question 14

Which of the following is an undesirable electromagnetic effect on a device(s)?

  • A. (EMC)
  • B. Electromagnetic interference (EMI)
  • C. Radio frequency interference (RFI)
  • D. Fast transients
  • E. Electrostatic discharge (ESD)


Answer : B

Question 15

During a site survey you notice that several CRT displays in the vicinity of the engineering
copy center have sporadic visual distortion. What is the MOST likely cause?

  • A. Electromagnetic interference (EMI)
  • B. Radio frequency interference (RFI)
  • C. (EMC)
  • D. Fast transients
  • E. Electromagnetic discharge (ESD)


Answer : A

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