RCDD EXAM 2026-2027 QUESTIONS AND
CORRECT ANSWERS GRADED A+
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)
B. 30 mm (5.12 in)
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.
B. You should provide a minimum separation of 610 mm (24 in).
,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
C. Reactive
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
A. Unbalanced circuit
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
D. 1 PHz
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)
A. Electromagnetic interference (EMI)
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)
B. Electromagnetic interference (EMI)
, 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)
A. Electromagnetic interference (EMI)
The ability of a device to withstand electromagnetic disturbances from another
device is:
A. Electromagnetic interference (EMI)
B. Radio Frequency Interference (RFI)
C. (EMC)
D. Fast transients
E. Electrostatic Discharge (ESD)
C. (EMC)
Which of the following is NOT a source of electromagnetic interference (EMI)?
A. Copiers -
CORRECT ANSWERS GRADED A+
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)
B. 30 mm (5.12 in)
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.
B. You should provide a minimum separation of 610 mm (24 in).
,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
C. Reactive
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
A. Unbalanced circuit
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
D. 1 PHz
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)
A. Electromagnetic interference (EMI)
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)
B. Electromagnetic interference (EMI)
, 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)
A. Electromagnetic interference (EMI)
The ability of a device to withstand electromagnetic disturbances from another
device is:
A. Electromagnetic interference (EMI)
B. Radio Frequency Interference (RFI)
C. (EMC)
D. Fast transients
E. Electrostatic Discharge (ESD)
C. (EMC)
Which of the following is NOT a source of electromagnetic interference (EMI)?
A. Copiers -
