Stay Grounded 250
Electrical system grounding will stabilize the voltage to earth during normal operation: true or false
What is True
Please Refer: NEC Code 250.4(A)(1)
Most electricians refer to ____ switches as “toggle switches” or “wall switches.”
general
pressure
float
snap
SNAP
An interrupting rating is a(n) ____ rating, and measures the fuse’s or circuit breaker’s ability to safely open an electrical circuit under fault conditions, such as an overload, short circuit, or ground fault.
recommended
minimum
average
maximum
Maximum
LED lighting could be called “____ lighting.”
low-state
fluid-state
transistor-state
solid-state
Solid-State lighting
The feeder overcurrent protection is sized for the ____ of the feeder conductor.
voltage drop
resistance
dimensions
ampacity
Ampacity
Main bonding jumpers and system bonding jumpers shall not be made of copper: True or False
False
Please Refer: NEC Code 250.28(A)
An ac–dc general-use snap switch is always marked with the ____.
-current and voltage rating
-year of manufacture
-resistance
-phrase “ac-dc switch”
current and voltage rating
The purpose of a(n) ____ device is to protect the circuit wiring and devices and to some extent the equipment served by the circuit.
overvoltage protection
overcurrent protection
multioutlet
branch circuit
overcurrent protection
For fluorescent and HID luminaires, the volt-ampere allowance is based on the rating of the ____.
ballast
tubing
filament
phosphor
Ballast
Conductors for 480Y/277-volt systems are generally brown, orange, ____ for the ungrounded conductors and gray for the grounded conductor..
green
blue
yellow
black
Yellow
In case of AC system 3-phase, 4 wire wye connected system having voltage range between 50V and 1000V which of the following is grounded:
Neutral Conductor
One phase conductor
Mid point of one phase winding
Neutral Conductor
Please Refer: NEC Code 250.20(B)(2)
When using cable for the wiring of 3-way switches, NEC 200.7(C)(1) permits the use of a conductor with insulation that is white or ____ or has three continuous white stripes (not too common) as a switch supply only if the conductor is permanently re-identified by painting or other effective means.
red
green
gray
black
GRAY
____ is the ability of the equipment (the entire assembly) to withstand a fault current equal to or less than the rating for the length of time it takes the specified overcurrent device to open the circuit to the equipment.
Short-circuit rating
Interrupting capacity
Open-circuit rating
Interrupting minimum
Short-circuit rating
The light-producing element in the incandescent lamp is a ____ wire called the filament.
tungsten
metal halide
silver
copper
Tungsten
NEC® 408.36(A) stipulates that if the panelboard contains snap switches with a rating of ____ amperes or less, the panelboard overcurrent protection is not permitted to exceed 200 amperes.
15
50
30
100
30 Amperes
In case of high impedance grounding systems, grounding system conductor shall not be smaller than ___ copper and ____ aluminum:
10 AWG, 8 AWG
8 AWG. 6 AWG
6 AWG. 8 AWG
8 AWG, 4 AWG
8 AWG. 6 AWG
Please Refer: NEC Code: 250.36(B)
A 3-way switch has a common terminal to which the switch blade is always connected, and it has two other terminals called ____ terminals.
mover
mobile
utility
traveler
traveler
In a Class 2 circuit, because the power source of the circuit is limited, ____ overcurrent protection is required.
minimum
circuit-breaker-based
no
fuse-based
NO
The installation of luminaires, lighting outlets, and supports is covered in Article 410 of the NEC®. Article 410 sets forth the basic requirements for the installation, commonly referred to as the “____.”
rough-in
light-up
pre-set
grounding
ROUGH-IN
In general, panelboards are constructed so the ____ run vertically for nearly the height of the panelboard.
receptacles
main feed busbars
branch circuits
cross feed buses
main feed busbars
Which of the following circuits cannot be grounded:
Question options:
Circuits for electric cranes operating over combustible fibers
Circuits for equipment within electrolytic cell working zone
Circuits in health care facilities
Circuits associated with fire water supply system
All are correct
All are correct
Please Refer: NEC Code 250.22
A ____ switch is used where it is desired to control a light or group of lights, or other load, from one switching point.
traveler
single-pole
four-way
three-way
Single-Pole
When sizing conductors and overcurrent protection, you must take 100 percent of the noncontinuous loads plus ____ percent of the continuous loads.
80%
125%
75%
100%
125%
Fluorescent lamps can be operated on a ____ circuit if the proper ballasts are used. A ballast for this type of system contains a current-limiting resistor that provides an inductive kick to start the lamp.
dimming
dc
high-frequency
flashing
DC or Direct Current
Unused openings in panelboards and switches should be ____.
marked as a pinch point
available for expansion
marked as a hazard point
closed
CLOSED