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Virginia (VA) Electronic/Communication Service (ESC)
Contractor Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION
This Comprehensive set of multiple choice questions is designed for the Virginia
Electronic/Communication Service (ESC) Contractor Exam, an open-book assessment
administered by PSI that evaluates a candidate’s proficiency across the breadth of
low-voltage systems operating at under 50 volts. The content spans grounding and
bonding techniques, conductor and cable selection (including fiber optic, coaxial, and
twisted-pair), low-voltage signaling and fire alarm circuits, computer network design
and cabling standards, sound and video systems, essential electrical and electronic
theory such as Ohm’s law, raceway and enclosure requirements, and proper use of
testing equipment, all in accordance with the 2020 National Electrical Code and
telecommunications wiring standards.
QUESTION 1
According to the NEC, what is the minimum size copper grounding electrode conductor
permitted for a communications system protector when connected to a ground rod?
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 6 AWG
CORRECT ANSWER: C
EXPERT RATIONALE: NEC 800.100 requires a minimum 10 AWG copper grounding
electrode conductor for communications protectors when connected to a made
electrode such as a ground rod.
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QUESTION 2
When bonding the metallic shield of a coaxial cable entering a building, the attachment
shall be made as close as practicable to the point of entrance.
A. True
B. False
C. Only if the cable is over 50 ft
D. Only for plenum-rated cable
CORRECT ANSWER: A
EXPERT RATIONALE: NEC 820.93 requires bonding the shield as close to the point of
entrance as practicable to limit potential differences and provide an effective grounding
path.
QUESTION 3
What is the maximum resistance to earth required by the NEC for a made electrode
used solely for grounding a telephone protector?
A. 5 ohms
B. 10 ohms
C. 25 ohms
D. No specific resistance requirement
CORRECT ANSWER: D
EXPERT RATIONALE: The NEC does not specify a maximum resistance for a single made
electrode used for communications grounding; if the resistance exceeds 25 ohms, a
second electrode is required per 250.53, but no specific upper limit is mandated.
QUESTION 4
In a low-voltage data installation, the intersystem bonding termination (IBT) must be
located at which location?
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A. Inside the main electrical panel
B. At the point of entry of the communications cable
C. At an accessible location near the service equipment
D. On the telecommunications rack in the data closet
CORRECT ANSWER: C
EXPERT RATIONALE: NEC 250.94 requires the IBT to be accessible, located near the
service equipment or meter enclosure, and connected to the grounding electrode
system to bond various systems together.
QUESTION 5
Which conductor in a CATV coaxial drop must be bonded to the building grounding
electrode system?
A. The center conductor
B. The outer metallic shield
C. Both the center conductor and shield
D. None, if it is fiber optic
CORRECT ANSWER: B
EXPERT RATIONALE: Per NEC 820.100, only the outer conductive shield of a coaxial cable
must be grounded to prevent voltage surges; the center conductor carries the signal
and is not directly bonded.
QUESTION 6
What is the primary reason for bonding the metallic raceway of a low-voltage signaling
circuit to the equipment grounding conductor?
A. Improve data speed
B. Reduce electromagnetic interference
C. Provide a fault current return path and touch potential equalization
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D. Eliminate the need for a separate grounding electrode
CORRECT ANSWER: C
EXPERT RATIONALE: Bonding ensures all metallic components remain at the same
potential, providing a path for ground-fault current and reducing shock hazards, as
required by NEC 250.4.
QUESTION 7
A ground rod used for a radio antenna mast must be a minimum of:
A. 4 ft in length, 3/8 in diameter
B. 6 ft in length, 1/2 in diameter
C. 8 ft in length, 5/8 in diameter
D. 10 ft in length, 3/4 in diameter
CORRECT ANSWER: C
EXPERT RATIONALE: NEC 810.21(J) requires that grounding electrodes for antenna
masts be at least 8 ft long, 5/8 in. diameter if rod-type, or equivalent.
QUESTION 8
The bonding conductor for a telecommunications primary protector shall run in what
manner?
A. As short and straight as practicable
B. In multiple loops for strain relief
C. Through a conduit isolated from other conductors
D. Along with the power feeders for convenience
CORRECT ANSWER: A
EXPERT RATIONALE: NEC 800.100(D) states the bonding conductor shall be kept as
short and straight as practicable to minimize impedance and surge energy.
Virginia (VA) Electronic/Communication Service (ESC)
Contractor Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION
This Comprehensive set of multiple choice questions is designed for the Virginia
Electronic/Communication Service (ESC) Contractor Exam, an open-book assessment
administered by PSI that evaluates a candidate’s proficiency across the breadth of
low-voltage systems operating at under 50 volts. The content spans grounding and
bonding techniques, conductor and cable selection (including fiber optic, coaxial, and
twisted-pair), low-voltage signaling and fire alarm circuits, computer network design
and cabling standards, sound and video systems, essential electrical and electronic
theory such as Ohm’s law, raceway and enclosure requirements, and proper use of
testing equipment, all in accordance with the 2020 National Electrical Code and
telecommunications wiring standards.
QUESTION 1
According to the NEC, what is the minimum size copper grounding electrode conductor
permitted for a communications system protector when connected to a ground rod?
A. 14 AWG
B. 12 AWG
C. 10 AWG
D. 6 AWG
CORRECT ANSWER: C
EXPERT RATIONALE: NEC 800.100 requires a minimum 10 AWG copper grounding
electrode conductor for communications protectors when connected to a made
electrode such as a ground rod.
,2|Page
QUESTION 2
When bonding the metallic shield of a coaxial cable entering a building, the attachment
shall be made as close as practicable to the point of entrance.
A. True
B. False
C. Only if the cable is over 50 ft
D. Only for plenum-rated cable
CORRECT ANSWER: A
EXPERT RATIONALE: NEC 820.93 requires bonding the shield as close to the point of
entrance as practicable to limit potential differences and provide an effective grounding
path.
QUESTION 3
What is the maximum resistance to earth required by the NEC for a made electrode
used solely for grounding a telephone protector?
A. 5 ohms
B. 10 ohms
C. 25 ohms
D. No specific resistance requirement
CORRECT ANSWER: D
EXPERT RATIONALE: The NEC does not specify a maximum resistance for a single made
electrode used for communications grounding; if the resistance exceeds 25 ohms, a
second electrode is required per 250.53, but no specific upper limit is mandated.
QUESTION 4
In a low-voltage data installation, the intersystem bonding termination (IBT) must be
located at which location?
,3|Page
A. Inside the main electrical panel
B. At the point of entry of the communications cable
C. At an accessible location near the service equipment
D. On the telecommunications rack in the data closet
CORRECT ANSWER: C
EXPERT RATIONALE: NEC 250.94 requires the IBT to be accessible, located near the
service equipment or meter enclosure, and connected to the grounding electrode
system to bond various systems together.
QUESTION 5
Which conductor in a CATV coaxial drop must be bonded to the building grounding
electrode system?
A. The center conductor
B. The outer metallic shield
C. Both the center conductor and shield
D. None, if it is fiber optic
CORRECT ANSWER: B
EXPERT RATIONALE: Per NEC 820.100, only the outer conductive shield of a coaxial cable
must be grounded to prevent voltage surges; the center conductor carries the signal
and is not directly bonded.
QUESTION 6
What is the primary reason for bonding the metallic raceway of a low-voltage signaling
circuit to the equipment grounding conductor?
A. Improve data speed
B. Reduce electromagnetic interference
C. Provide a fault current return path and touch potential equalization
, 4|Page
D. Eliminate the need for a separate grounding electrode
CORRECT ANSWER: C
EXPERT RATIONALE: Bonding ensures all metallic components remain at the same
potential, providing a path for ground-fault current and reducing shock hazards, as
required by NEC 250.4.
QUESTION 7
A ground rod used for a radio antenna mast must be a minimum of:
A. 4 ft in length, 3/8 in diameter
B. 6 ft in length, 1/2 in diameter
C. 8 ft in length, 5/8 in diameter
D. 10 ft in length, 3/4 in diameter
CORRECT ANSWER: C
EXPERT RATIONALE: NEC 810.21(J) requires that grounding electrodes for antenna
masts be at least 8 ft long, 5/8 in. diameter if rod-type, or equivalent.
QUESTION 8
The bonding conductor for a telecommunications primary protector shall run in what
manner?
A. As short and straight as practicable
B. In multiple loops for strain relief
C. Through a conduit isolated from other conductors
D. Along with the power feeders for convenience
CORRECT ANSWER: A
EXPERT RATIONALE: NEC 800.100(D) states the bonding conductor shall be kept as
short and straight as practicable to minimize impedance and surge energy.
