Year 2 Rocks!
15. For a 120/240 volt 3-ph, 4-wire system the voltage from the "high-leg" to ground is ____ volts.
a. 0
b. 120
c. 208
d. 240
What is 208 volts?
(c.)
26. A stairway between the 1st and 2nd floors of an office building with ___ to control the stairway lighting will not violate the NEC.
I. a 3-way switch at the 1st floor and a 3-way switch at the 2nd floor landing
II. a single-pole switch at the 1st floor landing
III. a single-pole switch at the 2nd floor landing
a. III only
b. I only
c. II or III only
d. I or II or III
e. II only
What is all three options- I or II or III?
(d.)
39. A 15-amp, multiwire branch circuit is connected to breakers 1 and 3 in a 120/208-volt, 3ø, 4-wire panelboard. If somewhere in the circuit the neutral and the "hot" from breaker 3 touch together, ______.
a. an overload will occur and the breaker will trip
b. a short circuit will occur and the breaker will trip
c. a ground fault will occur and the breaker will trip
d. the load will operate normally and the breaker will not trip
What is a short circuit will occur and the breaker will trip?
(b.)
52. RMC is to be installed under the playground next to a school. The minimum burial depth permitted is _____ inches.
a. 24
b. 0
c. 18
d. 6
e. 12
f. 4
What is 6 inches?
(d)
2. When Group D, Cat #3111 transformer secondary is delivering 100 amps to a three-phase load, ____ amps of current flows through each primary supply circuit conductor.
a. 14.4
b. 57.5
c. 25
d. 100
e. 75
f. 43.3
What is 43.3 amps?
(f.)
56. The total cross-sectional area of 5" Schedule 80 PVC is ____ in2.
a. 19.761
b. 10.713
c. 17.855
d. 5.535
e. 4.768
What is 17.855 in2?
(c.)
61. A switch box will contain the following:
(one) isolated ground receptacle
(one) 12/2 with ground AC cable (BX) with exterior connector
The shallowest switch box you can use for this installation is 3"x 2"x ____".
a. 2
b. 2 1/4
c. 2 1/2
d. 2 3/4
e. 3 1/2
What is 2 1/2"?
(c)
70. ____-grade receptacles are the highest grade receptacles manufactured by the electrical industry.
a. hospital
b. commercial
c. industrial
d. none of these
What is Hospital-grade receptacles?
(a.)
78. Recreational vehicles with two to five 15 or 20 ampere branch circuits shall have an attachment plug that shall be 2-pole, 3-wire grounding type, rated ____ amperes, 125 volts.
a. 30
b. 50
c. 15
d. 20
What is 30 amperes?
(a.)
35. What minimum size conductors are required to feed a 12.5 KW, 240-volt electric furnace operated at 240 volts? Size of conductors per 424.3(B). The branch-circuit OCPD is a circuit breaker that is rated for 75oC.
a. 6
b. 4
c. 8
d. 10
e. 3
What is 6?
(a.)
92. Large dry-type distribution-type transformer enclosures have steel bottoms that are punched _____.
a. so that a knockout center can be used to make underground conduit entries
b. so that the shipping weight is reduced
c. to provide for ventilation
d. to be able to run the ground rod wire through the holes
What is to provide for ventilation?
(c.)
97. If three singel-phase, 37.5 KVA transformers are connected together to form a three-phase delta bank, what will be the total KVA rating?
a. 64.95
b. 150
c. 21.65
d. 112 1/2
e. 37.5
What is 112 1/2 is the total KVA rating?
(d.)
101. A 120/240-volt, 1-ph, 3-wire panel is fed from a 50 KVA 1ø transformer that has Z=2.8% on its nameplate. The transformer is supplied power from a 2-pole breaker in a 277/480-volt, 3-ph, 4-wire panel. If X1 and X4 are connected together using a 4/0AWG copper jumper, ____ amps of current will flow through the 4/0.
a. 4296
b. 859
c. 991
d. 496
e. 7440
What is 7440 amps?
(e.)
18. The NEC permits the insulation for an ungrounded conductor to be ____ in color.
a. orange
b. black
c. brown
d. yellow
e. any of these
What is any of these?
(e.)
58. Where a section of trade size 3 LFMC is installed between two pull boxes that are 9" apart, a maximum of ____ 4/0 AWG THHN/THWN conductors can be installed.
a. 13
b. 23
c. 14
d. 9
e. 12
What is 14- 4/0 AWG THHN/THWN conductors?
(c.)
120. ____ speed is the theoretical speed of a motor based on the motor's number of poles and the line frequency.
a. Locked-rotor
b. Breakdown
c. Pull-up
d. Synchronous
What is Synchronous?
(d.)
28. A 200-amp breaker protects a feeder that originates in a 120/240-volt, 3-ph, 4-wire service panel in a movie theatre. Which of the following THHN/THWN conductors is the smallest size permitted for the feeder?
a. 4/0
b. 1
c. 2/0
d. 3/0
e. 1/0
What is 3/0?
(d.)
115. A(n) ____ ATS is designed for applications where maintenance, inspection and testing must be performed while maintaining continuous power to the load.
a. bypass isolation
b. manual bypass
c. isolation
d. maintenance bypass
What is bypass isolation?
(a.)
36. A 4/0 AWG conductor that is connected to a circuit breaker in a 120/208-volt, 3-ph, 4-wire panelboard can carry ____ amps of current inside the panel.
a. 260
b. 225
c. 230
d. 250
e. 195
What is 230 amps?
(c.)
102. Three 50 KVA, single-phase transformers are connected in a wye bank to provide 120/208-volt power. If the %Z is 2.4, this transformer bank capable of providing ___ amps of short-circuit current.
a. 17,348
b. 30,048
c. 8,681
d. 41,636
e. 26,042
What is 17,348 amps?
(a.)
110. A load has nameplate ratings of: 240V and 150A. The circuit you have available to supply the load is 208 volts. The catalog number for a B-B transformer that can operate the load at its rated voltage is ____.
a. 21110
b.11111
c. 11108
d. 21113
e. 21111
f. 11110
What is 21111?
(e.)
73. Five dedicated circuits are to be installed in PVC conduit. Each circuit feeds an isolated ground receptacle that is installed in a metal box. The circuit conductors are connected to breakers 4, 6, 8, 32, and 34 in a 120/240-volt, 1ø, 3-wire panel. Per the NEC, the fewest number of grounding conductors you are permitted to install in the PVC is _____.
a. 5
b. 3
c. 6
d. 2
e. 1
What is 2?
(d.)
30. Which of the following requires that a GFPE device be installed?
a. 1200-A safety switch with 800-A fuses for a 480/277-volt, 3ø, 4-wire service
b. 277/480-volt, 3ø, 4-wire switchgear with a 1200-Amp Main Breaker
c. Both a and b
d. Neither a nor b
What is both a and b?
(c.)
81. In temporary installations, receptacle shall not be connected to the same ungrounded conductor of multiwire circuits that supply ______.
a. GFCI receptacles
b. temporary lighting
c. emergency lighting
d. motors
What is temporary lighting?
(b.)
NEC 590.4(D)
55. Which of these trade size 1 1/4 raceways has the smallest cross-sectional area?
a. LFMC
b. EMT
c. RMC
d. FMC
e. Schedule 80 PVC
What is Schedule 80 PVC?
(e.)