Residential Electrician Exam #4 Solved Rated A+
A ground rod is required to be driven a MINIMUM depth of _____ feet into the soil.
a) 4
b) 6
c) 8
d) 10 - ANSWER-C: 8
Ref: 250.53(G)
A luminaire shall be supported independently of the outlet box when it weighs more than
_____ pounds, unless the outlet box is listed for the weight to be supported.
a) 6
b) 25
c) 35
d) 50 - ANSWER-D: 50
Ref: 314.27(B)
A metal box or terminal fitting having separately bushed holes for each conductor shall
be used whenever change is made from a conduit to _____.
a) knob-and-tube wiring
b) non-metallic sheathed cable
c) type AC cable
d) type MC cable - ANSWER-A: knob-and-tube wiring
Ref: 300.16(A)
All 15- and 20-ampere, single-phase, 125-volt receptacle outlets located at LEAST
_____ from the inside walls of a swimming pool shall be provided with GFCI protection.
a) 10 feet
b) 15 feet
c) 20 feet
d) 25 feet - ANSWER-C: 20 feet
Ref: 680.22(A)(4)
Concealed knob and tube wiring shall be permitted to be used only for _____.
a) dwellings units
b) extensions of existing installations
c) accessible installations
d) installing temporary wiring - ANSWER-B: extensions of existing installations
Ref: 394.10(1)
Disregarding exceptions, the MINIMUM size underground service lateral conductors
permitted by the NEC® is _____.
a) 8 AWG copper
b) 6 AWG copper
c) 4 AWG aluminum
d) 2 AWG aluminum - ANSWER-A: 8 AWG copper
, Ref: 230.31(B)
Disregarding exceptions, where residential lighting outlets are installed in interior
stairways, there shall be a wall switch provided ______.
a) near the stairs
b) every seven steps
c) at the top and bottom of the stairs if there are more than six steps
d) at any convenient location - ANSWER-C: at the top and bottom of the stairs if there
are more than six steps
Ref: 210.70(A)(2)(c)
Electric water heaters for swimming pools shall have the heating elements subdivided
into loads NOT exceeding _____.
a) 32 amperes
b) 36 amperes
c) 48 amperes
d) 60 amperes - ANSWER-C: 48 amperes
Ref: 680.9
For the purpose of determining box fill, size 12 AWG copper conductors with THHN
insulation are to be calculated at _____ per conductor in the box.
a) 1.75 cubic inches
b) 2.00 cubic inches
c) 2.25 cubic inches
d) 2.50 cubic inches - ANSWER-C: 2.25 cubic inches
Ref: Tbl. 314.16(B)
How many size 12/2 AWG with ground, type NM cables are permitted to be installed in
an outlet box with a total volume of 18 cubic inches when the box contains a duplex
receptacle outlet?
a) one
b) two
c) three
d) four - ANSWER-B: two
Ref: Tbl. 314.16(B); 314.16(B)(4)
Sol:
18 cu. in. (box) / 2.25 cu. in. (#12 wire) = 8 wires (allowable fill)
8 wires (allowable fill) - 2 wires (device) = 6 wires may be added
Size 12/2 with ground NM = 3 wires in cable
6 wires (allowed) / 3 wires per cable = 2 size 12 AWG NM cables are permitted in the
box
In dwelling units, all 125 volt, single-phase, 15 and 20 ampere receptacle outlets
installed within 6 feet of the outside edge of a sink in a laundry room shall _____.
a) have a weatherproof cover
b) have AFCI protection
A ground rod is required to be driven a MINIMUM depth of _____ feet into the soil.
a) 4
b) 6
c) 8
d) 10 - ANSWER-C: 8
Ref: 250.53(G)
A luminaire shall be supported independently of the outlet box when it weighs more than
_____ pounds, unless the outlet box is listed for the weight to be supported.
a) 6
b) 25
c) 35
d) 50 - ANSWER-D: 50
Ref: 314.27(B)
A metal box or terminal fitting having separately bushed holes for each conductor shall
be used whenever change is made from a conduit to _____.
a) knob-and-tube wiring
b) non-metallic sheathed cable
c) type AC cable
d) type MC cable - ANSWER-A: knob-and-tube wiring
Ref: 300.16(A)
All 15- and 20-ampere, single-phase, 125-volt receptacle outlets located at LEAST
_____ from the inside walls of a swimming pool shall be provided with GFCI protection.
a) 10 feet
b) 15 feet
c) 20 feet
d) 25 feet - ANSWER-C: 20 feet
Ref: 680.22(A)(4)
Concealed knob and tube wiring shall be permitted to be used only for _____.
a) dwellings units
b) extensions of existing installations
c) accessible installations
d) installing temporary wiring - ANSWER-B: extensions of existing installations
Ref: 394.10(1)
Disregarding exceptions, the MINIMUM size underground service lateral conductors
permitted by the NEC® is _____.
a) 8 AWG copper
b) 6 AWG copper
c) 4 AWG aluminum
d) 2 AWG aluminum - ANSWER-A: 8 AWG copper
, Ref: 230.31(B)
Disregarding exceptions, where residential lighting outlets are installed in interior
stairways, there shall be a wall switch provided ______.
a) near the stairs
b) every seven steps
c) at the top and bottom of the stairs if there are more than six steps
d) at any convenient location - ANSWER-C: at the top and bottom of the stairs if there
are more than six steps
Ref: 210.70(A)(2)(c)
Electric water heaters for swimming pools shall have the heating elements subdivided
into loads NOT exceeding _____.
a) 32 amperes
b) 36 amperes
c) 48 amperes
d) 60 amperes - ANSWER-C: 48 amperes
Ref: 680.9
For the purpose of determining box fill, size 12 AWG copper conductors with THHN
insulation are to be calculated at _____ per conductor in the box.
a) 1.75 cubic inches
b) 2.00 cubic inches
c) 2.25 cubic inches
d) 2.50 cubic inches - ANSWER-C: 2.25 cubic inches
Ref: Tbl. 314.16(B)
How many size 12/2 AWG with ground, type NM cables are permitted to be installed in
an outlet box with a total volume of 18 cubic inches when the box contains a duplex
receptacle outlet?
a) one
b) two
c) three
d) four - ANSWER-B: two
Ref: Tbl. 314.16(B); 314.16(B)(4)
Sol:
18 cu. in. (box) / 2.25 cu. in. (#12 wire) = 8 wires (allowable fill)
8 wires (allowable fill) - 2 wires (device) = 6 wires may be added
Size 12/2 with ground NM = 3 wires in cable
6 wires (allowed) / 3 wires per cable = 2 size 12 AWG NM cables are permitted in the
box
In dwelling units, all 125 volt, single-phase, 15 and 20 ampere receptacle outlets
installed within 6 feet of the outside edge of a sink in a laundry room shall _____.
a) have a weatherproof cover
b) have AFCI protection
