Residential Electrician Exam 1 Questions and Answers
with complete solution
Ferrous metal enclosures for grounding electrode conductors shall be _____.
a) electrically continuous
b) electrically isolated
c) not permitted
d) rigid metal conduit (RMC) only
A: electrically continuous
Ref: 250.64(E)
Unless listed for the control of other loads, general use dimmer switches shall only be
used to control _____.
a) switched receptacles for cord-connected incandescent luminaires
b) permanently installed incandescent luminaires
c) ceiling fans with luminaires
d) holiday decorative lighting
B: permanently installed incandescent luminaires
Ref: 404.14(E)
All 125-volt, single-phase, 15- and 20-ampere receptacles installed in residential
garages shall be _____.
I) protected by a listed arc-fault interrupter
II) provided with ground-fault circuit-interrupter protection
a) I only
b) II only
c) both I and II
d) neither I nor II
B: II only
Ref: 210.8(A)(2); 210.12(B)
The MAXIMUM allowable ampacity of size 18 AWG fixture wire is _____ amperes.
a) 12
b) 10
c) 8
d) 6
D: 6
Ref: Tbl. 402.5
A receptacle outlet installed for a gas or electric clothes dryer in the laundry room of a
dwelling unit must be installed within at LEAST _____ feet of the intended location of
the dryer.
a) 6
b) 4
c) 10
d) 3
A: 6
Ref: 210.50(C)
, Which of the following listed conductors are required to have overcurrent protection on a
residential electric service?
a) grounding conductors
b) bonding conductors
c) identified conductors
d) ungrounded conductors
D: ungrounded conductors
Ref: 290.9
Given: a 40-gallon electric water heater has a nameplate rating of 4,500 watts at 240
volts. What is the MAXIMUM standard size circuit breaker the NEC permits to protect
the water heater?
a) 20 amperes
b) 25 amperes
c) 30 amperes
d) 45 amperes
C: 30 amperes
Ref: 422.11(E)(3); 240.6(A); Current Formula
Sol:
I = P/E
I = 4500 va / 240 volts
I = 18.75 amps x 150 percent
I = 28.1 amperes
If a cable or raceway enters an enclosure such as a meter base, above uninsulated live
parts in a wet location, the fittings used to connect the enclosure must be _____ for wet
locations.
a) identified
b) marked
c) suitable
d) listed
D: listed
Ref: 312.2(A)
In general, the power supply cord to a mobile home shall have a MAXIMUM rating of
_____.
a) 50 amperes
b) 60 amperes
c) 100 amperes
d) 125 amperes
A: 50 amperes
Ref: 550.10(A)
A 150 kVA, single-phase transformer having a secondary voltage of 120/240 is to be
installed at a multi-family dwelling. The current available at the secondary is _____
amperes.
a) 329
b) 421
c) 625
d) 729
with complete solution
Ferrous metal enclosures for grounding electrode conductors shall be _____.
a) electrically continuous
b) electrically isolated
c) not permitted
d) rigid metal conduit (RMC) only
A: electrically continuous
Ref: 250.64(E)
Unless listed for the control of other loads, general use dimmer switches shall only be
used to control _____.
a) switched receptacles for cord-connected incandescent luminaires
b) permanently installed incandescent luminaires
c) ceiling fans with luminaires
d) holiday decorative lighting
B: permanently installed incandescent luminaires
Ref: 404.14(E)
All 125-volt, single-phase, 15- and 20-ampere receptacles installed in residential
garages shall be _____.
I) protected by a listed arc-fault interrupter
II) provided with ground-fault circuit-interrupter protection
a) I only
b) II only
c) both I and II
d) neither I nor II
B: II only
Ref: 210.8(A)(2); 210.12(B)
The MAXIMUM allowable ampacity of size 18 AWG fixture wire is _____ amperes.
a) 12
b) 10
c) 8
d) 6
D: 6
Ref: Tbl. 402.5
A receptacle outlet installed for a gas or electric clothes dryer in the laundry room of a
dwelling unit must be installed within at LEAST _____ feet of the intended location of
the dryer.
a) 6
b) 4
c) 10
d) 3
A: 6
Ref: 210.50(C)
, Which of the following listed conductors are required to have overcurrent protection on a
residential electric service?
a) grounding conductors
b) bonding conductors
c) identified conductors
d) ungrounded conductors
D: ungrounded conductors
Ref: 290.9
Given: a 40-gallon electric water heater has a nameplate rating of 4,500 watts at 240
volts. What is the MAXIMUM standard size circuit breaker the NEC permits to protect
the water heater?
a) 20 amperes
b) 25 amperes
c) 30 amperes
d) 45 amperes
C: 30 amperes
Ref: 422.11(E)(3); 240.6(A); Current Formula
Sol:
I = P/E
I = 4500 va / 240 volts
I = 18.75 amps x 150 percent
I = 28.1 amperes
If a cable or raceway enters an enclosure such as a meter base, above uninsulated live
parts in a wet location, the fittings used to connect the enclosure must be _____ for wet
locations.
a) identified
b) marked
c) suitable
d) listed
D: listed
Ref: 312.2(A)
In general, the power supply cord to a mobile home shall have a MAXIMUM rating of
_____.
a) 50 amperes
b) 60 amperes
c) 100 amperes
d) 125 amperes
A: 50 amperes
Ref: 550.10(A)
A 150 kVA, single-phase transformer having a secondary voltage of 120/240 is to be
installed at a multi-family dwelling. The current available at the secondary is _____
amperes.
a) 329
b) 421
c) 625
d) 729
