Electrical ? on D Flashcards
(123 cards)
1
Q
The minimum length for ground rod?
A
8ft
2
Q
Handful of questions can be answered in the definition sections of NFPA 72 and NEC
A
Tip
3
Q
There maybe a trick question that will . What kind of detector is needed for an elevator shaft that contains a sprinkler head with a certain heat rating. The answer is a heat detector that is lower rated than the sprinkler head
A
Tip
4
Q
Ohms law states that current through a conductor between two points is directly proportional to the voltage across two points
A
5
Q
How many hours are needed to renew you D licence every 3 years?
A
21 hours
6
Q
Receptacles used for circuits and equipment operating at less than 50 volts. Shall be a minimum rating of how many amps.?
A
15 amps
7
Q
Unlisted non conductive outside plant optical fiber cables shall not be permitted to be installed in which type of raceway.?
A
Flexible metal conduit
8
Q
When a combination of surface metallic raceways are used for both signaling/ lighting and power circuits. The different systems shall be run in a separate compartment. When is it NOT an acceptance means of identifying by the interior finish of the different system.?
A
Tagging
9
Q
The term faulty current is also called.?
A
Short circuit current
10
Q
Speakers are “audible textual appliance”
A
11
Q
Sound pressure is measured by using a.? –
A
A weighted scale
12
Q
ADA became law in .?
A
1992
13
Q
RMS is an effective value
A
14
Q
What is the power at a 4 ohm resistance load connected to a 120v power supply.?
A
3600W
15
Q
Askarel A group of nonflammable synthetic chlorinated hydrocarbons used a electrical industry Med kit
A
16
Q
What is the greatest root-meen square(effective) difference of potential between any 2 conductors of a circuit concerned as.?
A
Voltage
17
Q
Inverter turns DC into AC ,Rectifier turns AC into DC
A
18
Q
ADA -Annex J
A
19
Q
Reverse polarity on a ammeter will read zero
A
20
Q
, Megameter tests for shorts to ground(insulated)
A
21
Q
90 dba is permissible noise exposure for a limit of an 8 hr day. If exceeded hearing protection is required.
A
OSHA
22
Q
4 ft is the depth of pits when working on a contained and enclosed spaces
A
OSHA
23
Q
19 “ is the limit on intermediate members when on scaffolding.
A
OSHA
24
Q
10 or less employees on an emergency action plan can be communicating orally any more would require a written plan.
A
OSHA
25
5000lbs is the minimum breaking strength for fall protection
OSHA
26
6 feet is the length a 24 ft non self-supporting ladder should be from the vertical structure upon which its leaning.
OSHA
27
What color does Digsafe use to flag electrical lines
Red
28
Pad locks (lock out/Tag out) must be assigned to 2 people T or F
False
29
What PPE is recommended when walking around energized circuits? ??
----
30
What is the amount of current considered to be lethal ?
.1 amp
31
What are the 3 factors that affect the level of injury from electric shock.?
Current, Path, Time
32
What is the proper 3 steps procedure for testing a circuit for voltage.?
Check known circuit, check circuit in question, check a live circuit.
33
What type of environment is characterized by” easily light able, fibers and flying’s
Class 3
34
Which symbol indicates that explanatory material on the paragraph can be found in Annex A?
Asterisk
35
Bored holes in wood members shall be kept at least how far from the nearest edge?
1 1/4 inches
36
What is the standard length of ridged conduit?
10 ft
37
Can Type NM cable be used as a wiring method in place of assembly?
No
334.12
38
Under what conditions can a plug and receptacle be used as a disconnecting means on a portable x-ray?
120 V 30 Amp
660.5
39
How long do you have to pass the D licence exam after being approved?
1 Year
40
What is the minumum fixed bend radius for 3/4 Flexible metal tubing (FMT)
5 inches
Table 360.24 (B)
41
A continuous load is when the maximum current is expected to continue for at least how many hours?
3 Hours
42
An existing 4 inch square box has knockouts open. What must be done to the openings?
Metal plugs must be used
43
The width of the work space in front of electric equipment that is 48" wide, shall be a minimum of ?
48 Inches
44
A single receptacle is placed on a individual 20 amp circuit. What is the minimum required rating for this receptacle?
20 Amps
45
The general lighting load for stores is?
3 VA square foot
46
What is the minimum height of the fencing around a high voltage switch yard is?
18 feet
47
The maximum number of service disconnects for a single service is?
6
48
In dwellings units,guest rooms of hotels and motels, over-current devices shall not be located in?
Bathrooms
49
Electrical equipment shall be installed in a neat and workman like manner. True or False
True
110.12
50
Where an attic space contains equipment that requires servicing such as an AC, where is the switch for the required lighting outlet to be located?
At the usual point of entry to the attic.
210.70 (3)
51
310.16 (C) of NEC generally requires that conductors, where they are installed in raceways, shall be stranded when the conductor size is_____ or larger?
8 AWG
52
The title of Article 310 of NEC is?
Conductors for General wiring
53
According to 110.5 when the code refers only to a conductor size and the material of the conductor is not specified, the code intends the use of?
Copper wire
54
Table 8 Chapter 9 of the NEC, "Conductor Properties" Ohm/1000 ft is
Ohms per one thousand feet
55
How many strands of wire are used in the make up of 4/0 AWG stranded conductor?
19 strands
56
Branch circuits supplying lighting fixtures in a dwelling units are limited to ____ volts normal between conductors
120V
210.6(A)
57
A branch circuit that supplies two or more receptacles or outlets for lighting or appliances is known as a____ branch circuit?
General purpose
210.4
58
The general rule for spacing of the required dwelling unit receptacles is that any space less than_____ feet does NOT require a receptacle outlet
6 Feet
| 210.52(A)(1)
59
Which of the following wiring methods is NOT permitted to be used in interior wiring?
USE cable
338.12(B)
60
A 120v GFCI protected 20 amp branch circuit is installed underground in Type UF cable. The cable passed under a one family dwelling driveway. The minimum burial depth for the UF cable is____inches?
12 inches
300.5 Table
61
How many conditions does the NEC list whereby conductors shall be considered to be outside of a building or other structures?
6
225.30(A)
62
What part of Article 230 addresses service exceeding 1000 volts normal?
Part IV pg 70-87
63
When voltage goes up and resistance goes down what happens to current?
Current goes up
64
How much space will one# 14 AWG and one #12 AWG take up in a box?
4,25 inch
314.16(B)
65
The board has a right to know if the applicant has been
Convicted felon, misdemeanor or charged with a crime
66
The frequency of inspection for a piece of equipment that requires semiannual inspections requires inspection the be
Between 4 to 8 months from the last inspection
67
An insulated ground conductor may be identified by a continuous white or gray outer finish along its entire length if the conductor is ?
#6 Awg or smaller
68
What is the total resistance of a 50 ohm, a 75 ohm and 100 ohm resister in a series circuit?
225 OHMs
RT=R1+R2+R3... in series
69
What is the total power of a parallel circuit with a 100v source 150 and 250 Ohms resisters?
106.67W
Look at Ohms law
70
The voltage source of a 25V , what is the current through a 15 ohm resistor that is connected in parallel with a 30 and 45 ohm resistor?
.0833
| Look at Ohms law
71
If a voltage drop across a resistor is 20 v and the current is .02 A what is the power dissipated in watts?
.04
| Look at Ohms law
72
What is used to measure resistance?
Ohmmeter
73
A resistor has color bands or red,violet,brown and gold . What is the resistance and tolerance of the resistor?
270 Ohms , 5%
74
If a parallel circuit has only two branches RT=
RT+ 1/R1+1/R2+1/R3
Look at Ohms law
75
Assume 3 resistors each having a value of 24 ohms are connected in parallel, What is the total resistance in ohms?
8 ohms
76
The total power used in a circuit ___ the power used by all parts
is equal to the sum of
77
The fact that total circuit resistance____ as resistance is added to a parallel circuit is easily misunderstood
Decreases
78
A series circuit has ___ paths for current flow?
one
79
____ is the force that pushes electrons through a resistance
Voltage
80
In a series circuit the ___ of all the voltage drops across all resistors must equal the _____
Sum, voltage applied to the circuit
81
The total amount of series resistance offered to the flow of current is___ to the sum of all the resistors in the circuit
inversely proportional
82
In a circuit with an applied voltage of 120v and a total resistance of 60 ohms how much current flows through each resistor?
2A
I= E/R
83
A series circuit has 2--- 100 ohm resistors and 2 --- 200 ohm resistors what is the total resistance?
600 ohms
| RT=R1+R2+R3
84
If a circuit requires___ current and ____voltage sources can be connected in parallel to combine
Higher and the same
85
If a circuit is open current ____flow
will not
86
Where is the number expressed in a code paragraph in U.S. customary units and S.I. units(metric) such as for mounting height
The code permits use of one or the other
87
In a series circuit the ___is the same at any point in the circuit
Amperage
88
When the color silver is used in the multiplier band it means to divide the numeric value of the resistor by?
100
89
When the color silver is used in the multiplier band it means to divide the numeric value of the first 2 bands by?
10
90
Resistors that have a tolerance of plus/minus 20% have____ color bands?
4 color bands
91
The value of 6M-ohms is ___ohms
6 Million
92
____ resistors have only one ohmic value which cannot be changed or altered
Fixed
93
Bend radius of EMT
EMT 1/2=5", 3/4=6", 1"=8" and 1 1/2"=11"
| Ridged 1/2=6", 3/4=8" and 1"=11"
94
Box sizing Table in NEC is
314.16(A)
95
Permissible fill of a underfloor raceway is?
40%
96
What location is not suitable for MC cable?
Concrete
97
If a transformer has a 1 to 1 ratio it is a
Isolation transformer
98
Minimum radius of a steel ground rod?
5/8"
99
Maximum current of #16 AWG conductors is ?
10 Amps
100
How is a Ammeter connected to a circuit?
In series
101
Transformer 200 turns at 240v secondary has 100 turns. What is the secondary voltage?
120v
102
The unit of pressure that causes current to flow is?
Volts
103
On what date does everyone's D licence expire?
July 31
104
What is the value of resistor with yellow,violet and red?
4.7K
| resistors value chart
105
On what print would you find the breaker size?
Panel board schedule
106
What is the best instrument to measure resistance on a large scale?
Megohmmeter
107
An analog voltmeter is connected to a 24v DC circuit if the polarity is reversed what will the meter read?
Zero or fewer volts
108
What is the voltage drop of a 240v 24 amp single phase load located 160ft from the panel using #10 THHN?
9.5v
109
On what print would you find the the feeder size?
Power riser
110
AC current load consisting of 8 similar devices.Each rated 120v and 200ws. Whats the total current connected?
13.3 amps
| ohms law
111
2 24 v batteries connected in sires
| =
48V
112
When 2 conductors are separated by a insulator electrical energy can be stored and released.What is stored?
Capacitance
113
What is the total capacitance of 4 capacitors each rated to 20 micro farads connected in parallel?
80 micro farads
114
What does a multi meter test?
All listed choices
115
The first band on a resistor is blue . What is is designated number?
6
| resistors value chart
116
Find the power when you have 3 amp and 15 ohms?
135 Watts
| ohms law
117
If you have a change of address how long to you have to notify the board?
10 Days
118
What type of conduit is made of PVC and color coded for use ?
ENT
119
A device(outlet) is always counted as the largest size AWG in a box
pg 176 NFPA-70 314.16(A)
120
14/2 A device counts as 2 wires the clamp on the box counts as 1 wire.
12/2 A device counts as 4 wires and the clamp as 2 wires
pg 176 NFPA-70 314.16(A)
121
Class 2 is low Voltage Class 1-3 is High voltage (120v)
----
122
Spacing of supports for 18AWG through 8 AWG shall be supported no greater than 100 ft apart
----
123
Direct burial Table 300.5 pg 137 NFPA -70
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