Lesson 118 - First Semester Final Exam
4.5
The voltage is applied to the flashlight lamp when the 1.5-volt batteries are inserted in the flashlight, as shown at the right, is ___ volts.
12 4.5
Type NM cable must be supported within ___ inches of a box or fitting and at intervals not exceeding ___ feet, except where it is run horizontally through holes in wood or metal framing members.
13.367 (R = [Erated]2 ÷ Prated = 1202 ÷ 1750 = 8.229 ohms then: I = Ea ÷ R = 110 ÷ 8.229 = 13.367 A)
What is the current drawn by a hair dryer if the nameplate supplies the following information and it is operated at 110 volts: 1750 watts 120 volts
I only
When batteries are connected in parallel, the ___ supplied to the connected load increases. I. current II. voltage
as close together as possible
When individual conductors of the same circuit are run in trenches, these should be installed ___.
23,500
23.5 V = ___ mV
590
According to the NEC®, temporary installations are covered in Article ___.
6.67 min.
If a pump discharges 600 gallons of water in 2.5 minutes, how long will it take to discharge 1,600 gallons of water?
resistance
Opposition to current flow is generally termed ________.
Radio Frequency Interference
RFI is an abbreviation for ___.
68'-113/32"
Refer to Figure 105.1511. The length of b is ___ where a = 122/3 yd and c = 78 ft.
series
See Figure 116.425. These elements are ___ connected.
.2963
512 cubic inches = ___ cubic feet
under all circumstances
The 125-volt, 20-ampere receptacles installed to serve kitchen countertops are required to have GFCI protection ___.
15
Where 10 AWG THHN/THWN copper circuit conductors are connected to a 15-amp circuit breaker, the circuit is considered to be a ___-amp branch circuit.
True
A 20-ampere, 125-volt single receptacle installed in a dwelling garage for a freezer would require GFCI protection.
7.35 (Vd = 2KIL ÷ cma = (2)(12)(10)(200) ÷ 6530 = 7.35 volts)
A 240-volt branch circuit supplies a resistive heating load of 10 amps. The distance from the panel to the heater is 200'. Using 12 AWG THHN copper, what is the voltage drop on the wire? Use K = 12.
grounded conductor
A GFCI receptacle or circuit breaker will "trip" when it senses a difference in the amount of current flowing in the ungrounded conductor versus the amount of current flowing in the ___.
all of these
A ___ is a unit of an electrical system that is intended to carry or control electric energy as its primary function. Select one: a. receptacle b. switch c. device d. all of these
is not permitted
A pendant luminaire mounted in a clothes closet ___.
7
A single 4" × 21/8" × 21/8" (handy) device box can hold no more than ___ 14 AWG conductors.
12
A surface-mounted incandescent luminaire (light fixture) mounted in a clothes closet must maintain a clearance of at least ___ inches to the storage area.
24
According to the Table Notes in Chapter 9 in the NEC®, any section of EMT, rigid metal conduit, IMC, etc that has a length of ___ inches or less is considered to be a nipple.
Section 400.5
Ampacities for flexible cords are determined using ___ in the NEC®.
True
An enclosed channel of metal or nonmetallic materials designed expressly for holding wires, cables, or busbars is the definition of a raceway.
Yes
Are lighting fixtures in residential bedroom areas required to have AFCI protection?
higher than
During a ground fault, the current flow through the circuit breaker is ___ the current flow during normal operation. Assume this is a properly connected circuit.
grounded
During normal operation, the current flows out to a 120-volt load on the "hot" and returns on the ___ conductor. Assume this is a properly connected circuit.
120
For a 120/240-volt, 1Ø, 3-wire supply system the voltage from L2 to ground is ___.
C only
For the receptacle shown in Figure 112.216, an ungrounded conductor is connected at Point ___.
True
In walls or ceilings constructed of sheetrock, brick, or concrete block, it is acceptable to have the front edge of the box set back as much as 1/4 inch from the finish surface.
I
Point ___ on the drawing shown in Figure 112.211 is the point where the grounding conductor is connected.
64 ((8 yd. × 16 yd.) ÷ 2 = 64 sq. yd.)
Refer to Figure 107.1312. Dimension A = 8 yards Dimension B = 16 yards The triangular area is ___ sq. yd.
15
Section 240.4(D)(3) in the NEC® tells us that, in general, the maximum overcurrent protection permitted for a 14 AWG copper conductor is ___ amperes.
34.25 (R1 = E1-rated ÷ I1 -rated = 220 ÷ 31.4 = 7.0064 & R2 = E2-rated ÷ I2 -rated = 220 ÷ 31.4 = 7.0064 RT = R1 + R2 = 14.0127 then IT = I1 = I2 = Ea ÷ RT = 480 ÷ 14.0127 = 34.2546 amps)
See Figure 116.425. I1 = Current through Element 1 = ___ amps.
210.52(H)
The Code reference that specifies the required number of receptacles in a dwelling hallway is ___. Select N/A (not applicable) if there is not a Code reference for this.
damp
The NEC® considers an installation under a covered walkway or canopy to be a ___ location.
the circuit conductors between the final overcurrent device protecting the circuit and the outlet(s)
The NEC® defines a branch circuit as ___.
358.30(B)
The NEC® requirements for securing EMT in horizontal runs are located in Section ___.
4110
The circular mil area of a 14 AWG bare copper conductor is ___ cmils
120
This duct heater contains two heating elements that are connected as shown. The fixed or "hot" resistance of each of the two elements is 22 ohms. See Figure 115.314. The voltage dropped across each element when the duct heater is connected to the 240-volt circuit is ___ volts.
line surges and spikes
Transient voltage surge suppressors are used to minimize the damage to connected equipment caused by ___.
decreases resistance
What effect does using a larger size wire (example: 10 AWG instead of a 14 AWG) have on the resistance of the circuit?
NEC
What is the basic standard that governs all electrical work?
20.5 ([25] × .82 = 20.5 amp)
What is the corrected ampacity of a #14 THHN/THWN copper conductor where the temperature is 120°F?
shall or shall not
What word or words must be included in any Code statement that is mandatory?
11/4
When running NMC through a bored hole in a stud, the nearest edge of the bored hole shall not be less than ___ inch(es) from the face of the stud unless the cable is protected by a 1/16-inch-thick metal steel plate(s).
3'
Where installing EMT, the maximum distance (without using exceptions) between the first support and a box is ___.
28.8 (ampacity = [30] × .96 = 28.80 amps)
Where the temperature is 90°F the adjusted current-carrying capacity of a 12 AWG THHN/THWN copper conductor is ___ amps.