TEXAS RESIDENTIAL WIREMAN EXAM
1. What is the primary purpose of a grounding electrode
system in a residential electrical installation?
A. To increase voltage to branch circuits
B. To provide a path for normal neutral current
C. To reduce conductor resistance
D. To provide a path to earth for lightning and fault currents
Rationale: The grounding electrode system connects the
electrical system to earth to stabilize voltage and safely
dissipate lightning, surges, and fault currents. It is not intended
to carry normal neutral current during standard operation.
2. According to the NEC, what is the minimum cover
requirement for PVC conduit under a residential driveway?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Rationale: NEC Table 300.5 specifies minimum burial depths.
Residential driveways generally require 18 inches of cover for
PVC conduit containing branch circuits rated 120 volts or more.
3. Which conductor is identified by white or gray insulation?
A. Equipment grounding conductor
B. Ungrounded conductor
C. Grounded conductor (neutral)
D. Bonding jumper
,Rationale: NEC requirements identify grounded conductors with
white or gray insulation. Ungrounded conductors are typically
black, red, or other colors except green, white, or gray.
4. What is the maximum number of 12 AWG current-carrying
conductors permitted in a 3/4-inch EMT conduit under
standard conditions?
A. 9
B. 12
C. 16
D. 20
Rationale: NEC Chapter 9, Table 1 and Annex C provide conduit
fill limits. Under standard conditions, up to 16 THHN 12 AWG
conductors are permitted in 3/4-inch EMT.
5. A 20-amp branch circuit supplying receptacles in a
dwelling must use a minimum conductor size of:
A. 14 AWG copper
B. 12 AWG copper
C. 10 AWG copper
D. 8 AWG copper
Rationale: NEC Table 310.16 and Article 240 require 12 AWG
copper conductors for 20-amp branch circuits. Fourteen AWG
conductors are limited to 15 amps.
6. What type of protection is required for receptacles
installed in residential bathrooms?
A. Arc-fault protection only
B. Surge protection only
,C. Ground-fault circuit interrupter protection
D. Isolated ground protection
Rationale: NEC 210.8 requires GFCI protection for bathroom
receptacles because of the increased risk of electrical shock in
wet or damp environments.
7. Which NEC article covers grounding and bonding
requirements?
A. Article 110
B. Article 210
C. Article 250
D. Article 250
Rationale: NEC Article 250 contains the rules governing
grounding and bonding methods, conductor sizing, grounding
electrodes, and equipment bonding.
8. How many small-appliance branch circuits are required for
a dwelling kitchen?
A. One
B. Two or more
C. Three exactly
D. Four
Rationale: NEC 210.11(C)(1) requires at least two 20-amp small-
appliance branch circuits for kitchen, pantry, breakfast room,
and dining area receptacles.
9. What is the minimum working clearance in front of a
120/240-volt residential panelboard?
, A. 24 inches
B. 30 inches
C. 36 inches
D. 48 inches
Rationale: NEC 110.26 requires a minimum depth of working
space of 36 inches in front of electrical equipment operating at
600 volts or less.
10. Which conductor is permitted to be bare in
residential wiring?
A. Neutral conductor
B. Ungrounded conductor
C. Traveler conductor
D. Equipment grounding conductor
Rationale: Equipment grounding conductors are commonly bare
or green insulated. Neutral conductors must be insulated and
identified white or gray.
11. What is the purpose of a circuit breaker?
A. To increase amperage
B. To regulate voltage
C. To provide overcurrent protection
D. To prevent grounding
Rationale: Circuit breakers automatically open a circuit during
overloads or short circuits to protect conductors and equipment
from damage.
12. A receptacle installed outdoors at a dwelling must
have:
1. What is the primary purpose of a grounding electrode
system in a residential electrical installation?
A. To increase voltage to branch circuits
B. To provide a path for normal neutral current
C. To reduce conductor resistance
D. To provide a path to earth for lightning and fault currents
Rationale: The grounding electrode system connects the
electrical system to earth to stabilize voltage and safely
dissipate lightning, surges, and fault currents. It is not intended
to carry normal neutral current during standard operation.
2. According to the NEC, what is the minimum cover
requirement for PVC conduit under a residential driveway?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Rationale: NEC Table 300.5 specifies minimum burial depths.
Residential driveways generally require 18 inches of cover for
PVC conduit containing branch circuits rated 120 volts or more.
3. Which conductor is identified by white or gray insulation?
A. Equipment grounding conductor
B. Ungrounded conductor
C. Grounded conductor (neutral)
D. Bonding jumper
,Rationale: NEC requirements identify grounded conductors with
white or gray insulation. Ungrounded conductors are typically
black, red, or other colors except green, white, or gray.
4. What is the maximum number of 12 AWG current-carrying
conductors permitted in a 3/4-inch EMT conduit under
standard conditions?
A. 9
B. 12
C. 16
D. 20
Rationale: NEC Chapter 9, Table 1 and Annex C provide conduit
fill limits. Under standard conditions, up to 16 THHN 12 AWG
conductors are permitted in 3/4-inch EMT.
5. A 20-amp branch circuit supplying receptacles in a
dwelling must use a minimum conductor size of:
A. 14 AWG copper
B. 12 AWG copper
C. 10 AWG copper
D. 8 AWG copper
Rationale: NEC Table 310.16 and Article 240 require 12 AWG
copper conductors for 20-amp branch circuits. Fourteen AWG
conductors are limited to 15 amps.
6. What type of protection is required for receptacles
installed in residential bathrooms?
A. Arc-fault protection only
B. Surge protection only
,C. Ground-fault circuit interrupter protection
D. Isolated ground protection
Rationale: NEC 210.8 requires GFCI protection for bathroom
receptacles because of the increased risk of electrical shock in
wet or damp environments.
7. Which NEC article covers grounding and bonding
requirements?
A. Article 110
B. Article 210
C. Article 250
D. Article 250
Rationale: NEC Article 250 contains the rules governing
grounding and bonding methods, conductor sizing, grounding
electrodes, and equipment bonding.
8. How many small-appliance branch circuits are required for
a dwelling kitchen?
A. One
B. Two or more
C. Three exactly
D. Four
Rationale: NEC 210.11(C)(1) requires at least two 20-amp small-
appliance branch circuits for kitchen, pantry, breakfast room,
and dining area receptacles.
9. What is the minimum working clearance in front of a
120/240-volt residential panelboard?
, A. 24 inches
B. 30 inches
C. 36 inches
D. 48 inches
Rationale: NEC 110.26 requires a minimum depth of working
space of 36 inches in front of electrical equipment operating at
600 volts or less.
10. Which conductor is permitted to be bare in
residential wiring?
A. Neutral conductor
B. Ungrounded conductor
C. Traveler conductor
D. Equipment grounding conductor
Rationale: Equipment grounding conductors are commonly bare
or green insulated. Neutral conductors must be insulated and
identified white or gray.
11. What is the purpose of a circuit breaker?
A. To increase amperage
B. To regulate voltage
C. To provide overcurrent protection
D. To prevent grounding
Rationale: Circuit breakers automatically open a circuit during
overloads or short circuits to protect conductors and equipment
from damage.
12. A receptacle installed outdoors at a dwelling must
have:
