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WorksheetsEL06EANIYRAAHS
Total questions: 69
Worksheet time: 2hrs 18mins
Name
Class
Date
1.
The highest current rating of an Edison-base plug fuse is:
a)
30 A
b)
60 A
c)
100 A
d)
200 A
2.
Edison-base plug fuses may be used only in:
a)
New work
b)
Existing installations under specified conditions
c)
Motor control panels
d)
Motor circuits
3.
Which of the following is a nonstandard ampere rating for a plug fuse?
a)
15 A
b)
20 A
c)
30 A
d)
35 A
4.
The maximum size fuse allowed to protect a No. 14 AWG THW conductor is
a)
10A
b)
15 A
c)
20 A
d)
25 A
5.
When a circuit breaker trips, its operating handle will be in which of the following positions?
a)
Closed (energized) position
b)
Open position
c)
Halfway between the ON and OFF positions
d)
No change
6.
Plug fuses of 15 ampere and lower rating must be identified by what type of window configuration?
a)
Round
b)
Hexagonal
c)
Square
d)
Octagonal
7.
Which of the following conductors need overcurrent protection on a residential electric service?
a)
Grounded conductor
b)
Bonding conductor
c)
Ungrounded Conductors
d)
Equipment grounding conductor
8.
A circuit feeding three single-phase motors with full-load current ratings of 40, 20 and 20 amperes, respectively, requires the following dual-element time-delay fuse size:
a)
110 A
b)
150 A
c)
200 A
d)
250 A
9.
A nontime-delay fuse protects a circuit with all motor loads with the largest motor drawing a full-load current of 40 amperes, and two other motors drawing a full-load current of 15 amperes each. What fuse size should be used?
a)
100 A
b)
150 A
c)
175 A
d)
250 A
10.
An “AFCI receptacle” is known as a(n):
a)
Arc Resistant Outlet
b)
Upstream parallel arc fault protector
c)
Branch Circuit type AFCI
d)
Combination device
11.
Conductors may be tapped, without overcurrent protection at the tap, to a feeder or transformer secondary if certain conditions are met. If the ampacity of the tap conductor is not less than the combined computed loads on the circuits supplied by the tap conductor, the length of the tap conductor cannot exceed:
a)
5 ft
b)
15 ft
c)
10 ft
d)
25 ft
12.
Where must an overcurrent device be located in a circuit?
a)
At the point where the condutor receives
b)
At the last outlet on the circuit
c)
On the line side of the electric meter its supply
d)
At the first fitting or connector in the circuit
13.
The fuse in Figure 6-2 is known as:
a)
Edison-base plug fuse
b)
Edison-base cartridge fuse
c)
Type S plug fuse
d)
Non renewable cartridge fuse
14.
The fuse in Figure 6-3 is known as:
a)
Despard plug fuse
b)
Dual-element time-delay plug fuse
c)
Type S plug fuse
d)
Renewable cartridge fuse
15.
The fuse in Figure 6-4 is known as:
a)
Dual-element time-delay cartridge fuse
b)
Type S plug fuse
c)
Nontime-delay cartridge fuse
d)
Non renewable cartridge fuse
16.
The fuse in Figure 6-5 is known as:
a)
Dual-element time-delay cartridge fuse
b)
Type S plug fuse
c)
Type S fuse adapter
d)
Non renewable cartridge fuse
17.
The fuse clips in Figure 6-6 are known as:
a)
Class A fuse rejection clips
b)
Type D fuse rejection clips
c)
Class R fuse rejection clips
d)
Non renewable cartridge fuse
18.
If a multiwire branch circuit supplies line-to-line loads, the branch-circuit protective device must open each:
a)
A) All ungrounded conductors simultaneously
b)
B) Grounded conductor
c)
C) Ungrounded conductor individually
d)
D) Bonding conductor
19.
The largest standard rating for fuses and inverse time circuit breakers is:
a)
A) 1000 amperes
b)
B) 1600 amperes
c)
C) 1200 amperes
d)
D) 6000 amperes
20.
To meet NEC regulations, fuses or circuit breakers connected in parallel must be:
a)
A) Assembled by the electrician or technician on the job
b)
B) Encased in a PVC housing
c)
C) Factory assembled in parallel
d)
D) Rated over 200 amperes
21.
Supplementary overcurrent devices shall:
a)
A) Be required to be readily accessible and within sight of the equipment
b)
B) Not be required to be readily accessible
c)
C) Not be allowed under any conditions
d)
D) Be connected only in parallel or series-parallel
22.
One combination that is considered by the NEC to be equivalent to an overcurrent trip unit is:
a)
A) Pole-mounted transformer and overcurrent relay
b)
B) Submersible transformer and overcurrent relay
c)
C) Autotransformer and overcurrent relay
d)
D) Current transformer and overcurrent relay
23.
When a fuse or circuit breaker is used for circuit protection, the fuse or overcurrent trip unit shall be connected:
a)
A) In series
b)
B) In series and parallel
c)
C) In parallel
d)
D) In tandem
24.
At what point must a branch-circuit overcurrent protection device be placed in an electrical system?
a)
A) At the equipment ground location
b)
B) Where the conductor being protected receives its supply
c)
C) At a tap on the conductor being protected
d)
D) At the outlet where power is consumed
25.
The rating of the overcurrent protective device for a circuit supplying a hermetic motorcompressor must be at least what percent of the nameplate rated-load current?
a)
A) 50%
b)
B) 75%
c)
C) 115%
d)
D) 150%
26.
A multiwire branch circuit protected by fuses may supply only:
a)
A) Half line to line loads and half line to
b)
B) Half line to neutral loads to full or trip line
c)
C) Line to line loads neutral loads
d)
D) Line to neutral loads to other loads
27.
What is the minimum interrupting rating of an unmarked branch-circuit fuse?
a)
A) 5,000 amperes
b)
B) 10,000 amperes
c)
C) 15,000 amperes
d)
D) 20,000 amperes
28.
A feeder tap less than 25 feet long does not require overcurrent protection at the tap if the ampacity of the tap conductor is at least:
a)
A) 50% of the feeder conductor
b)
B) 40% of the feeder conductor
c)
C) 331/3% of the feeder conductor
d)
D) 20% of the feeder conductor
29.
When designing or installing circuits for diagnostic equipment in health care facilities, what is the minimum percentage allowed for the momentary ampacity of the equipment when sizing branch-circuit conductors and the overcurrent protection?
a)
A) 25%
b)
B) 50%
c)
C) 75%
d)
D) 100%
30.
The rated ampacity of conductors and overcurrent devices of a feeder for two or more branch circuits supplying X-ray equipment for non-medical or non-dental use must not be less than 100% of the momentary demand rating of the two largest pieces of X-ray equipment plus what percent of the momentary ratings of other X-ray apparatus?
a)
A) 5%
b)
B) 10%
c)
C) 15%
d)
D) 20%
31.
What is the maximum overcurrent device rating for each resistance welder connected to an electrical system?
a)
A) Not over 100% of the rated primary current of the welder
b)
B) Not over 200% of the rated primary current of the welder
c)
C) Not over 300% of the rated primary current of the welder
d)
D) Not over 400% of the rated primary current of the welder
32.
What is the maximum overcurrent device rating that may be used for each AC transformer or DC rectifier arc welder?
a)
A) Not over 100% of the rated primary current of the welder
b)
B) Not over 200% of the rated primary current of the welder
c)
C) Not over 300% of the rated primary current of the welder
d)
D) Not over 400% of the rated primary current of the welder
33.
Each autotransformer 600 volts, nominal, or less shall be protected by an individual overcurrent device. How must this device be connected in relation to the autotransformer?
a)
A) In parallel with each ungrounded input conductor
b)
B) In parallel with each grounded conductor
c)
C) In series with each ungrounded input conductor
d)
D) In series with each grounded conductor
34.
Such overcurrent devices as described in Question 6-33 must have a rating not exceeding a certain percentage of the rated full-load input current of the autotransformer. What is this percentage?
a)
A) 110%
b)
B) 125%
c)
C) 150%
d)
D) 200%
35.
If an autotransformer has a full-load input current of 40 amperes, what is the maximum overcurrent protection device rating allowed?
a)
A) 45 amperes
b)
B) 50 amperes
c)
C) 60 amperes
d)
D) 70 amperes
36.
In an autotransformer, overcurrent devices shall not be installed:
a)
A) In parallel with the output conductors
b)
B) In parallel with the shunt winding
c)
C) In series with the output conductors
d)
D) In series with the shunt winding
37.
A grounding autotransformer is used to create a three-phase, 4-wire distribution system from a three-phase, 3-wire ungrounded system. At what percent must the overcurrent device be set to trip in case of an overload?
a)
A) 100% of the transformer’s continuous current per phase or neutral rating
b)
B) 110% of the transformer’s continuous current per phase or neutral rating
c)
C) 125% of the transformer’s continuous current per phase or neutral rating
d)
D) 150% of the transformer’s continuous current per phase or neutral rating
38.
What must the continuous neutral current rating be for an autotransformer used to create a three-phase, 4-wire distribution system from a three-phase, 3-wire ungrounded system?
a)
A) It must be sufficient to handle the minimum neutral unbalanced load
b)
B) It must be sufficient to handle the maximum unbalanced load
c)
C) It must be sufficient to handle 75% of the neutral unbalanced load
d)
D) It must be sufficient to handle 50% possible neutral unbalanced load
39.
What is the maximum overcurrent rating that may be used for dimmer controls for stage lighting in theaters?
a)
A) 100% of the dimmer rating
b)
B) 110% of the dimmer rating
c)
C) 125% of the dimmer rating
d)
D) 150% of the dimmer rating
40.
If a dimmer control is rated at 2000 watts on a 120-volt single-phase circuit, what is the maximum overcurrent protection allowed for this dimmer?
a)
A) 15 amperes
b)
B) 20 amperes
c)
C) 30 amperes
d)
D) 40 amperes
41.
What is the maximum overcurrent protection allowed on circuits feeding stage equipment such as footlights, border lights, etc?
a)
A) 15 amperes
b)
B) 20 amperes
c)
C) 30 amperes
d)
D) 40 amperes
42.
What is the minimum branch circuit and maximum overcurrent protection rating for a circuit supplying a household electric range rated at 83/4 kW or more?
a)
A) 20 amperes
b)
B) 30 amperes
c)
C) 40 amperes
d)
D) 50 amperes
43.
What is the minimum number of circuits allowed to feed a household-type appliance with surface heating elements having a maximum demand of more than 60 amperes?
a)
1
b)
2
c)
3
d)
4
44.
(What is the minimum number of circuits allowed to feed a household-type appliance with surface heating elements having a maximum demand of more than 60 amperes? ) What is the maximum overcurrent protection allowed for each of the circuits described?
a)
A) 30 amperes
b)
B) 40 amperes
c)
C) 50 amperes
d)
D) 60 amperes
45.
What is the maximum rating of overcurrent devices used to protect circuits feeding infrared lamp heating appliances in commercial and industrial applications?
a)
A) 30 amperes
b)
B) 40 amperes
c)
C) 50 amperes
d)
D) 60 amperes
46.
. How must direct-current conductors used in electroplating systems be protected?
a)
A) Fuses or circuit breakers
b)
B) A current-sensing device that operates
c)
C) Other approved means by the authority having jurisdiction
d)
D) Any of the above a disconnecting means
47.
Where the allowable current rating of a busway does not correspond to a standard rating of overcurrent device, what rating is permitted?
a)
A) The next lower rating
b)
B) No overcurrent protection is required
c)
C) The next higher rating
d)
D) None of the above
48.
If the allowable current rating of a busway is 46 amperes, what is the maximum allowable rating of the overcurrent device?
a)
A) 40 amperes
b)
B) 50 amperes
c)
C) 60 amperes
d)
D) 70 amperes
49.
Omission of overcurrent protection is permitted at points where busways are reduced in size, provided that the smaller busway length does not exceed what distance?
a)
A) 10 feet
b)
B) 20 feet
c)
C) 30 feet
d)
D) 50 feet
50.
(Omission of overcurrent protection is permitted at points where busways are reduced in size, provided that the smaller busway length does not exceed what distance? Ans: ) In order to comply with NEC regulations what must the current rating of the smaller busway be in Question 6-49?
a)
A) One-third the rating or setting of the overcurrent device next back on the line
b)
B) Half the rating of the overcurrent device next back on the line
c)
C) Three-fourths the rating of the overcurrent device next back on the line
d)
D) Two-thirds the rating of the overcurrent device next back on the line
51.
What type of overcurrent device is required on a busway system where a branch circuit or subfeeder is tapped from the main busway?
a)
A) Internally operable circuit breaker
b)
B) Internally operable fusible switch
c)
C) Externally operable circuit breaker or externally operable fusible switch
d)
D) None is required
52.
When the overcurrent devices in Question 6-51 are mounted out of reach and contain disconnecting means, what provisions must be provided for operating the disconnecting means from the floor?
a)
A) Ropes
b)
B) Chains
c)
C) Sticks
d)
D) Any of the above
53.
When the allowable ampacity of a cablebus system does not correspond to a standard rating of overcurrent protection devices, what size overcurrent device is permitted?
a)
A) The next lower standard size
b)
B) The next higher standard size
c)
C) A device not exceeding 80% of the cablebus rating
d)
D) A device not exceeding 75% of the cablebus rating
54.
If a cablebus system is rated at 94 amperes, what is the maximum allowable overcurrent protection device rating?
a)
A) 90 amperes
b)
B) 95 amperes
c)
C) 100 amperes
d)
D) 105 amperes
55.
Mobile home disconnecting means shall be located not less than ____ above finished grade or working platform.
a)
A) 8 feet
b)
B) 6 feet
c)
C) 4 feet
d)
D) 2 feet
56.
The branch-circuit conductors to one or more units of information technology equipment shall have an ampacity of what percent of the total connected load?
a)
A) 200
b)
B) 125
c)
C) 100
d)
D) 80
57.
Circuit breakers used as switches for high intensity discharge lighting (HID) must be listed and marked:
a)
A) Listing and marking not required
b)
B) HID
c)
C) Intensity rated
d)
D) SWD
58.
A circuit breaker with a slash rating of 120/240 volts is rated for what voltage to ground?
a)
A) 120 volts to ground
b)
B) 240 volts to ground
c)
C) Any voltage up to 240
d)
D) None of these
59.
(A circuit breaker with a slash rating of 120/240 volts is rated for what voltage to ground? Ans: ) The circuit breaker in question 6-58 is permitted to be installed in which of the following systems?
a)
A) Solidly-grounded system
b)
B) Ungrounded system
c)
C) Ungrounded system in RV parks
d)
D) All of these
60.
Where a power supply enters a recreational vehicle, what is the maximum distance the supply may run inside the vehicle before it must be provided with overcurrent protection?
a)
A) 6 inches
b)
B) 8 inches
c)
C) 10 inches
d)
D) 18 inches
61.
Constant-voltage generators, except ac generator exciters, must be protected from overload by all but which of the following?
a)
A) Inherent design
b)
B) Circuit breakers and fuses
c)
C) Protective relays
d)
D) Fusible link
62.
What overcurrent requirements are specified for grounded conductors?
a)
A) An overcurrent device must be provided in parallel for every conductor that is intentionally grounded
b)
B) An overcurrent device must be provided in series for every conductor that is intentionally grounded
c)
C) No overcurrent device is permitted in series with any conductor that is intentionally grounded
d)
C) An overcurrent device must be provided in parallel for every conductor that is intentionally grounded
63.
(What overcurrent requirements are specified for grounded conductors? Ans: ) One exception to the rule as stated in Question 6-62 is:
a)
A) Where the overcurrent device opens all conductors of the circuit, including the grounded conductor, and is so designed that no pole can operate independently
b)
B) When used on a three-phase, 4-wire circuit
c)
C) Where each pole may be operated independently
d)
D) None of the above
64.
An insulated grounded conductor shall have insulation that is:
a)
A) Service rated
b)
B) Green
c)
C) Suitable for use as an ungrounded conductor
d)
D) Listed for underground use
65.
Where must overcurrent devices in non-power-limited fire alarm circuits be located?
a)
A) At the load on the circuit
b)
B) At the main service panel
c)
C) At the point where the conductor to be protected receives its supply
d)
D) None of the above
66.
What is the smallest standard plug-fuse rating for use on residential 120-volt branch circuits?
a)
A) 10 amperes
b)
B) 12 amperes
c)
C) 15 amperes
d)
D) 20 amperes
67.
In general, feeder and branch-circuit conductors must be protected by overcurrentprotective devices connected:
a)
A) Within 2 feet of the point where the conductors receive their supply
b)
B) Within 4 feet of the point where the conductors receive their supply
c)
C) At the immediate point where the conductors receive their supply
d)
D) Within 12 feet of the point where the conductors receive their supply
68.
A conductor installed on the uspply side of a service that insures that required electrical conductivity between metal parts is known as a:
a)
A.) Bonding jumper,supply-side
b)
B.) Supply-side electric conductor
c)
C.) Low-impedance bonding jumper
d)
D.) Redundant ground, supply-side
69.
At what point must a branch-circuit overcurrent protection device be placed in an electrical system?
a)
A) At the equipment ground location
b)
B) Where the conductor being protected receives its supply
c)
C) At a tap on the conductor being protected
d)
D) At the outlet where power is consumed
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