Transcript Master Examination Practice Drill #1 2011

Master Examination
Practice Drill #3 2011
O 1. Given: Two (2) rigid metal conduits (RMC)
are to support a weatherproof 18 cu. In.
device box, with threaded hubs, which
contains a 125-volt, 20-ampere receptacle
outlet. The conduits are to be threaded
wrench tight into the hubs and, in general,
shall be secured with at LEAST _____ of the
enclosure.
A. 8 inches
B. 12 inches
C. 18 inches
D. 24 inches
Question Answer
1.
C
Reference
NEC PG. #
314.23(F)
181
O 2. In general, if the cablebus system is rated
95 amperes, the MAXIMUM allowable rating
of the overcurrent device used to protect the
cablebus is _______.
A. 80 amperes
B. 90 amperes
C. 95 amperes
D. 100 amperes
Question Answer
2.
D
Reference
NEC PG. #
370.5
240.4(B)(2)&(3)
240.6(A)
227
90
91
O 3. A twenty-five (25) ft. long tap conductor
tapped from a 100 ampere rated feeder
conductor, shall have an ampacity of NOT
less than ________.
A. 50 amperes
B. 75 amperes
C. 25 amperes
D. 33.3 amperes
Question Answer
3.
D
Reference
NEC PG. #
240.21(B)&(B)(2)(1) 92&93
100 amperes/3 = 33.3 amperes
O 4. Disregarding exceptions, bonding
between Class I locations and the point of
grounding for service equipment may be
done by _________.
A. Double locknuts
B. Bonding jumpers
C. Insulated bushings
D. Metal raceways
Question Answer
4.
B
Reference
NEC PG. #
501.30(A)
381
O 5. Determine the demand load, in VA, on the
ungrounded service-entrance conductors,
for the general-lighting and receptacles for a
25,000 sq. ft. office building that has one
hundred-fifty (150) general-purpose duplex
receptacles. Consider the service
overcurrent protection device is NOT listed
for continuous use.
A. 112,075 VA
B. 106,000 VA
C. 90,200 VA
D. 127,875 VA
Question
Answer
Reference
NEC PG. #
5.
D
Tbl. 220.12
220.14(I)
63
63
220.44
Tbl. 220.44
Art. 100
230.42(A)(1)
64
64
27
82
25,000 sq. ft. x 3.5 VA x 125% (lighting)
= 109,375 VA
150 receptacles x 180 VA each = 27,000VA
1st 10,000 VA @ 100%
= 10,000 VA
27,000 VA – 10,000 VA = 17,000 VA @ 50% =
8,500VA
Total
= 127,875 VA
O 6. When an electrical service is required to
have a grounded conductor present, what is
the smallest grounded conductor permitted
for an electric service using size 1000 kcmil
copper undergrounded (phase) conductors?
A. 3/0 AWG copper
B. 2/0 AWG copper
C. 1/0 AWG copper
D. 4/0 AWG copper
Question Answer
6.
B
Reference
NEC PG. #
250.24(C)(1)
Tbl. 250.66
105
115
O 7. Determine the MINIMUM number of 20-
ampere, 277-volt, general-lighting branch
circuits required for a 150,000 sq. ft.
department store, when the actual
connected lighting load is 400 kVA,
A. 72 branch circuits
B. 82 branch circuits
C. 91 branch circuits
D. 102 branch circuits
Question Answer
7.
C
Reference
NEC PG. #
210.19(A)91)
210.11(B)
52
51
400 kVA = 400,000 VA x 125% (continuous load) = 500,000 VA (bldg.)
277 volts x 20 amperes = 5540 VA (one circuit)
500,000 VA. (bldg. lighting)
5,540 VA (one circuit)
= 90.2 = 91 circuits
*NOTE – Circuits need only to be installed to service the connected load.
O 8. Where a two-gang box contains two (2)
single-pole switches, unless the box is
equipped with permanently installed
barriers, the voltage between the switches
shall NOT be in excess of _______.
A. 120 volts
B. 277 volts
C. 240 volts
D. 300 volts
Question Answer
8.
D
Reference
NEC PG. #
404.8(B)
268
O 9. An aluminum grounding electrode shall
be _________.
A. Installed at least 18 inches above the
earth
B. Installed at least 24 inches above the
earth
C. In direct earth burial
D. Prohibited
Question Answer
9.
D
Reference
NEC PG. #
250.52(B)(2)
112
O 10. A panelboard is limited to 42 overcurrent
protective devices where ________.
A. The panelboard is a power panelboard
B. The panelboard is a “split-bus” type
panelboard
C. The panelboard supplies lighting
branch-circuits only
D. One is installed
Question Answer
10.
B
Reference
NEC PG. #
408.36, Ex. 2
276
O 11. When rigid polyvinyl chloride conduit
(PVC) is used to enclose conductors feeding
a wet-niche luminaire in a permanently
installed swimming pool, a ______ insulated
copper grounding conductor shall be
installed in this conduit, unless a listed lowvoltage lighting system not requiring
grounding is used.
A. 12 AWG
B. 10 AWG
C. 8 AWG
D. 6 AWG
Question Answer
11.
C
Reference
NEC PG. #
680.23(B)(2)(b)
581
O 12. In general, what is the largest size
transformer, in kVA, that may be installed in
an area or room that is NOT constucted in a
fire-resistant manner?
A. 75 KVA
B. 112 ½ KVA
C. 150 KVA
D. 50 KVA
Question Answer
12.
B
Reference
NEC PG. #
450.21(B)
352
O 13. When calculating the total load of an
office building, and the number of generalpurpose receptacles to be installed is not yet
determined, an additional load of _____ voltamp(s) per square foot is required for the
receptacle outlets.
A. One
B. Two
C. One-Half
D. Three
Question Answer
13.
A
Reference
NEC PG. #
220.14(K)(2)
63
O 14. When sizing time-delay Class CC fuses
for motor branch-circuit, short-circuit and
ground-fault protection, they are to be sized
at the same value as ________.
A. inverse-time circuit breakers
B. Nontime-delay fuses
C. Instantaneous trip circuit breakers
D. Adjustable trip circuit breakers
Question Answer
14.
B
Reference
NEC PG. #
Tbl. 430.52, Note 1
323
O 15. Conductors other than service-entrance
conductors shall be permitted to be installed
in a cable tray with service-entrance
conductors provided __________.
A. A solid fixed barrier of material
compatible with the cable tray is
installed to separate the systems
B. The conductors are not in excess of 480
volts to ground
C. The voltage between the conductors is
not in excess of 600 volts
D. The conductors have equal insulation
and temperature ratings
Question Answer
15.
A
Reference
NEC PG. #
203.44, Ex
82
O 16 The MAXIMUM allowable ampacity of a
size 750 kcmil XHHW aluminum conductor
where there are six (6) current-carrying
conductors in the raceway, installed in a dry
location, where the ambient temperature
will reach 22°C is ________
A. 323.40 amperes
B. 365.40 amperes
C. 361.92 amperes
D. 348.00 amperes
Question
Answer
Reference
NEC PG. #
16.
C
Tbl. 310.15(B)(16)
Tbl. 310.15(B)(2)(a)
Tbl. 310.15(B)(3)(a)
154
150
152
Size 750 kcmil AL ampacity (before derating) = 435 amperes
435 amps x 1.04 (temp correction) x .8 (adj. factor) = 361.92 amperes
O 17. In which of the following locations is a
cable tray prohibited to be installed?
A. Basement
B. Storage Rooms
C. Sealed Ceiling Spaces
D. When Passing Through a Wall
Question Answer
17.
C
Reference
NEC PG. #
392.18 (D)&(E)
240
O 18. What is the MINIMUM size copper common
grounding electrode conductor required to run
through a building to four (4) separately derived
systems (transformers) each having size 3/0
AWG copper secondary conductors.
A. 4 AWG
B. 2 AWG
C. 3/0 AWG
D. 8 AWG
Question Answer
18.
C
Reference
NEC PG. #
250.30(A)(6)(a)(1)
108
O 19. Where a commercial building has a 600
ampere, 3-phase, 208Y/120 volt service
supplied with two (2) paralled sets of size
350 kcmil copper conductors installed in
separate raceways, determine the MINIMUM
size aluminum grounding electrode
conductor permitted to the metal water
piping system used as the grounding
electrod.
A. 250 kcmil
B. 4/0 AWG
C. 3/0 AWG
D. 2/0 AWG
Question Answer
19.
B
Reference
NEC PG. #
250.66
Tbl. 250.66
115
115
350 kcmil x 2 conductors = 750 kcmil
*NOTE – A size 4/0 AWG aluminum grounding electrode
conductor should be selected
O 20. The NEC permits trade size 3/8 in.
flexible metal conduit (FMC) to be used to
enclose tap conductors for luminaires,
provided the length of the FMC does NOT
exceed __________.
A. 4 feet
B. 6 feet
C. 8 feet
D. 10 feet
Question Answer
20.
B
Reference
NEC PG. #
348.20(A)(2)c.
206
O 21. What is the MAXIMUM distance allowed
to support intermediate metal conduit (IMC)
from a junction box, where structural
members do not readily permit fastening?
A. 3 feet
B. 5 feet
C. 6 feet
D. 8 feet
Question Answer
21.
B
Reference
NEC PG. #
342.30(A)(2)
203
O 22. All of the following listed copper
conductors are to be installed in an
electrical metallic tubing (EMT) that is in
excess of 24 inches long.
 24-size 10 AWG with TW insulation
 10-size 10 AWG with THW insulation
 14-size 12 AWG with THHN insulation
Determine the MINIMUM trade size of EMT
required.
A. 2 in.
B. 2 ½ in.
C. 3 in.
D. 3 ½ in.
Question
Answer
Reference
NEC PG. #
22.
A
Chpt. 9, Tbl. 5
Chpt. 9, Tbl. 4
717&718
712
Size 10 AWG TW = .0243 sq. in. x 24 = .5832 sq. in.
Size 10 AWG THW = .0243 sq. in. x 10 = .2430 sq. in.
Size 12 AWG THNN = .0133 sq. in. x 14 = .1862 sq. in.
TOTAL = 1.1024 sq. in.
*NOTE – Trade size 2 inch EMT with a permitted fill of
1.342 sq. in. @ 40% should be selected
O 23. When combination surface nonmetallic
raceways are used both for signaling and for
power and lighting circuits, the different
systems shall be ________.
A. Prohibited
B. Run in the same compartment
C. Separated by at least ½ in.
D. Run in separate compartments
Question Answer
23.
D
Reference
NEC PG. #
388.70
238
O 24. When sizing fuses for a branch circuit
serving a hermetic refrigerant motorcompressor, the device shall NOT exceed
____ of the rated load current marked on
the nameplate of the equipment.
A. 115 percent
B. 125 percent
C. 175 percent
D. 225 percent
Question Answer
24.
D
Reference
NEC PG. #
440.22(A)
343
O 25. Where rigid metal conduit (RMC) is used
to protect a grounding conductor, the
conduit must ________.
A. Be isolated from the grounding
conductor
B. Be electrically continuous from cabinet
to ground clamps
C. Be identified with green paint
D. Not be connected to or touching the
ground clamp
Question Answer
25.
B
Reference
NEC PG. #
250.64(E)
114
Click here to advance to nontimed drill
O 1. Given: Two (2) rigid metal conduits (RMC)
are to support a weatherproof 18 cu. In.
device box, with threaded hubs, which
contains a 125-volt, 20-ampere receptacle
outlet. The conduits are to be threaded
wrench tight into the hubs and, in general,
shall be secured with at LEAST _____ of the
enclosure.
A. 8 inches
B. 12 inches
C. 18 inches
D. 24 inches
Question Answer
1.
C
Reference
NEC PG. #
314.23(F)
181
O 2. In general, if the cablebus system is rated
95 amperes, the MAXIMUM allowable rating
of the overcurrent device used to protect the
cablebus is _______.
A. 80 amperes
B. 90 amperes
C. 95 amperes
D. 100 amperes
Question Answer
2.
D
Reference
NEC PG. #
370.5
240.4(B)(2)&(3)
240.6(A)
227
90
91
O 3. A twenty-five (25) ft. long tap conductor
tapped from a 100 ampere rated feeder
conductor, shall have an ampacity of NOT
less than ________.
A. 50 amperes
B. 75 amperes
C. 25 amperes
D. 33.3 amperes
Question Answer
3.
D
Reference
NEC PG. #
240.21(B)&(B)(2)(1) 92&93
100 amperes/3 = 33.3 amperes
O 4. Disregarding exceptions, bonding
between Class I locations and the point of
grounding for service equipment may be
done by _________.
A. Double locknuts
B. Bonding jumpers
C. Insulated bushings
D. Metal raceways
Question Answer
4.
B
Reference
NEC PG. #
501.30(A)
381
O 5. Determine the demand load, in VA, on the
ungrounded service-entrance conductors,
for the general-lighting and receptacles for a
25,000 sq. ft. office building that has one
hundred-fifty (150) general-purpose duplex
receptacles. Consider the service
overcurrent protection device is NOT listed
for continuous use.
A. 112,075 VA
B. 106,000 VA
C. 90,200 VA
D. 127,875 VA
Question
Answer
Reference
NEC PG. #
5.
D
Tbl. 220.12
220.14(I)
63
63
220.44
Tbl. 220.44
Art. 100
230.42(A)(1)
64
64
27
82
25,000 sq. ft. x 3.5 VA x 125% (lighting)
= 109,375 VA
150 receptacles x 180 VA each = 27,000VA
1st 10,000 VA @ 100%
= 10,000 VA
27,000 VA – 10,000 VA = 17,000 VA @ 50% =
8,500VA
Total
= 127,875 VA
O 6. When an electrical service is required to
have a grounded conductor present, what is
the smallest grounded conductor permitted
for an electric service using size 1000 kcmil
copper undergrounded (phase) conductors?
A. 3/0 AWG copper
B. 2/0 AWG copper
C. 1/0 AWG copper
D. 4/0 AWG copper
Question Answer
6.
B
Reference
NEC PG. #
250.24(C)(1)
Tbl. 250.66
105
115
O 7. Determine the MINIMUM number of 20-
ampere, 277-volt, general-lighting branch
circuits required for a 150,000 sq. ft.
department store, when the actual
connected lighting load is 400 kVA,
A. 72 branch circuits
B. 82 branch circuits
C. 91 branch circuits
D. 102 branch circuits
Question Answer
7.
C
Reference
NEC PG. #
210.19(A)91)
210.11(B)
52
51
400 kVA = 400,000 VA x 125% (continuous load) = 500,000 VA (bldg.)
277 volts x 20 amperes = 5540 VA (one circuit)
500,000 VA. (bldg. lighting)
5,540 VA (one circuit)
= 90.2 = 91 circuits
*NOTE – Circuits need only to be installed to service the connected load.
O 8. Where a two-gang box contains two (2)
single-pole switches, unless the box is
equipped with permanently installed
barriers, the voltage between the switches
shall NOT be in excess of _______.
A. 120 volts
B. 277 volts
C. 240 volts
D. 300 volts
Question Answer
8.
D
Reference
NEC PG. #
404.8(B)
268
O 9. An aluminum grounding electrode shall
be _________.
A. Installed at least 18 inches above the
earth
B. Installed at least 24 inches above the
earth
C. In direct earth burial
D. Prohibited
Question Answer
9.
D
Reference
NEC PG. #
250.52(B)(2)
112
O 10. A panelboard is limited to 42 overcurrent
protective devices where ________.
A. The panelboard is a power panelboard
B. The panelboard is a “split-bus” type
panelboard
C. The panelboard supplies lighting
branch-circuits only
D. One is installed
Question Answer
10.
B
Reference
NEC PG. #
408.36, Ex. 2
276
O 11. When rigid polyvinyl chloride conduit
(PVC) is used to enclose conductors feeding
a wet-niche luminaire in a permanently
installed swimming pool, a ______ insulated
copper grounding conductor shall be
installed in this conduit, unless a listed lowvoltage lighting system not requiring
grounding is used.
A. 12 AWG
B. 10 AWG
C. 8 AWG
D. 6 AWG
Question Answer
11.
C
Reference
NEC PG. #
680.23(B)(2)(b)
581
O 12. In general, what is the largest size
transformer, in kVA, that may be installed in
an area or room that is NOT constucted in a
fire-resistant manner?
A. 75 KVA
B. 112 ½ KVA
C. 150 KVA
D. 50 KVA
Question Answer
12.
B
Reference
NEC PG. #
450.21(B)
352
O 13. When calculating the total load of an
office building, and the number of generalpurpose receptacles to be installed is not yet
determined, an additional load of _____ voltamp(s) per square foot is required for the
receptacle outlets.
A. One
B. Two
C. One-Half
D. Three
Question Answer
13.
A
Reference
NEC PG. #
220.14(K)(2)
63
O 14. When sizing time-delay Class CC fuses
for motor branch-circuit, short-circuit and
ground-fault protection, they are to be sized
at the same value as ________.
A. inverse-time circuit breakers
B. Nontime-delay fuses
C. Instantaneous trip circuit breakers
D. Adjustable trip circuit breakers
Question Answer
14.
B
Reference
NEC PG. #
Tbl. 430.52, Note 1
323
O 15. Conductors other than service-entrance
conductors shall be permitted to be installed
in a cable tray with service-entrance
conductors provided __________.
A. A solid fixed barrier of material
compatible with the cable tray is
installed to separate the systems
B. The conductors are not in excess of 480
volts to ground
C. The voltage between the conductors is
not in excess of 600 volts
D. The conductors have equal insulation
and temperature ratings
Question Answer
15.
A
Reference
NEC PG. #
203.44, Ex
82
O 16 The MAXIMUM allowable ampacity of a
size 750 kcmil XHHW aluminum conductor
where there are six (6) current-carrying
conductors in the raceway, installed in a dry
location, where the ambient temperature
will reach 22°C is ________
A. 323.40 amperes
B. 365.40 amperes
C. 361.92 amperes
D. 348.00 amperes
Question
Answer
Reference
NEC PG. #
16.
C
Tbl. 310.15(B)(16)
Tbl. 310.15(B)(2)(a)
Tbl. 310.15(B)(3)(a)
154
150
152
Size 750 kcmil AL ampacity (before derating) = 435 amperes
435 amps x 1.04 (temp correction) x .8 (adj. factor) = 361.92 amperes
O 17. In which of the following locations is a
cable tray prohibited to be installed?
A. Basement
B. Storage Rooms
C. Sealed Ceiling Spaces
D. When Passing Through a Wall
Question Answer
17.
C
Reference
NEC PG. #
392.18 (D)&(E)
240
O 18. What is the MINIMUM size copper common
grounding electrode conductor required to run
through a building to four (4) separately derived
systems (transformers) each having size 3/0
AWG copper secondary conductors.
A. 4 AWG
B. 2 AWG
C. 3/0 AWG
D. 8 AWG
Question Answer
18.
C
Reference
NEC PG. #
250.30(A)(6)(a)(1)
108
O 19. Where a commercial building has a 600
ampere, 3-phase, 208Y/120 volt service
supplied with two (2) paralled sets of size
350 kcmil copper conductors installed in
separate raceways, determine the MINIMUM
size aluminum grounding electrode
conductor permitted to the metal water
piping system used as the grounding
electrod.
A. 250 kcmil
B. 4/0 AWG
C. 3/0 AWG
D. 2/0 AWG
Question Answer
19.
B
Reference
NEC PG. #
250.66
Tbl. 250.66
115
115
350 kcmil x 2 conductors = 750 kcmil
*NOTE – A size 4/0 AWG aluminum grounding electrode
conductor should be selected
O 20. The NEC permits trade size 3/8 in.
flexible metal conduit (FMC) to be used to
enclose tap conductors for luminaires,
provided the length of the FMC does NOT
exceed __________.
A. 4 feet
B. 6 feet
C. 8 feet
D. 10 feet
Question Answer
20.
B
Reference
NEC PG. #
348.20(A)(2)c.
206
O 21. What is the MAXIMUM distance allowed
to support intermediate metal conduit (IMC)
from a junction box, where structural
members do not readily permit fastening?
A. 3 feet
B. 5 feet
C. 6 feet
D. 8 feet
Question Answer
21.
B
Reference
NEC PG. #
342.30(A)(2)
203
O 22. All of the following listed copper
conductors are to be installed in an
electrical metallic tubing (EMT) that is in
excess of 24 inches long.
 24-size 10 AWG with TW insulation
 10-size 10 AWG with THW insulation
 14-size 12 AWG with THHN insulation
Determine the MINIMUM trade size of EMT
required.
A. 2 in.
B. 2 ½ in.
C. 3 in.
D. 3 ½ in.
Question
Answer
Reference
NEC PG. #
22.
A
Chpt. 9, Tbl. 5
Chpt. 9, Tbl. 4
717&718
712
Size 10 AWG TW = .0243 sq. in. x 24 = .5832 sq. in.
Size 10 AWG THW = .0243 sq. in. x 10 = .2430 sq. in.
Size 12 AWG THNN = .0133 sq. in. x 14 = .1862 sq. in.
TOTAL = 1.1024 sq. in.
*NOTE – Trade size 2 inch EMT with a permitted fill of
1.342 sq. in. @ 40% should be selected
O 23. When combination surface nonmetallic
raceways are used both for signaling and for
power and lighting circuits, the different
systems shall be ________.
A. Prohibited
B. Run in the same compartment
C. Separated by at least ½ in.
D. Run in separate compartments
Question Answer
23.
D
Reference
NEC PG. #
388.70
238
O 24. When sizing fuses for a branch circuit
serving a hermetic refrigerant motorcompressor, the device shall NOT exceed
____ of the rated load current marked on
the nameplate of the equipment.
A. 115 percent
B. 125 percent
C. 175 percent
D. 225 percent
Question Answer
24.
D
Reference
NEC PG. #
440.22(A)
343
O 25. Where rigid metal conduit (RMC) is used
to protect a grounding conductor, the
conduit must ________.
A. Be isolated from the grounding
conductor
B. Be electrically continuous from cabinet
to ground clamps
C. Be identified with green paint
D. Not be connected to or touching the
ground clamp
Question Answer
25.
B
Reference
NEC PG. #
250.64(E)
114