Electrical True and False Flashcards
Clamps are used to mount the conduit to ceilings or walls using screws or bolts.
false
There are many types of individual electrical connectors which are categorized by level, function, and type of termination.
true
Air circuit breakers can be used for low-voltage and some medium-voltage circuits.
true
Liquidtight flexible metallic conduit (LFMC) is also called ‘liquidtight’ and ‘sealtight’.
true
Ribbon cables are quite flexible and can only handle both high and low voltage applications.
false
Cable is a single electrical conductor, whereas a wire is a group of cables covered in sheathing.
false
Since aluminum resists corrosion extremely well, aluminum conduits are preferred in locations where they would be exposed to large amounts of water, or corrosive substances.
true
Type 7 enclosures and Type 8 enclosures are non-hazardous location enclosure types.
false
Flexible metallic conduit (FMC) offers protection against impacts and corrosion, and can be used outdoors, buried or embedded.
false
Water resistant connectors can withstand being submerged and also provide protection for the electrical connections against water damage from splashes or occasional dampness.
false
Moisture/oil resistant connectors are designed to protect the electrical connections from damage caused by oil or moisture.
true
National Electrical Code is shorted as NEC.
true
Molded case external casing (circuit breakers) is generally used for medium voltage circuit breakers.
false
PVC conduits cannot be used in hazardous locations, as ground conductors or in locations where they are exposed to ambient temperatures over 50°C.
true
Motor control devices are designed to be controlled in a manual, automatic, or remote manner.
true
Vacuum circuit breakers are almost exclusively used in medium voltage circuits because of their compact size and high reliability and low maintenance.
true
Intelligent motor control devices use advanced microprocessors for controlling the power of electronic devices employed in an electric motor.
true
Electrical metallic tubing (EMT) is commonly known as ‘Greenfield’ or ‘flex’ conduit.
false
Air circuit breakers operate by increasing the arc voltage, which is the maximum voltage required to maintain an arc.
false
There are two contacts in a circuit breaker: a fixed contact and a floating contact.
true
Liquidtight flexible metallic conduit (LFMC) has an overall non-metallic outer covering that is not waterproof or resistant to cracking from sunlight exposure.
false
A very simple example of a motor control mechanism is a variable frequency drive (VFD), which adjusts motor voltage, changing the rotation speed.
true
Common wire sizes are 10, 12 and 14 - a higher number means a larger wire size, and affects the amount of power it can carry.
false
Each application requires a certain wire size for installation, and the right size for a specific application is determined by the code.
true
RMCs are both light and inexpensive.
false
To prevent drips and water-logging in the conduit runs, install drains at the lowest points of each run that might be affected, or at locations where water might get trapped and accumulate.
true
An installation may require a lot of bends, and bending conduits on location might damage them or reduce the internal diameter.
true
Conduit bodies are tubular units with openings at each end for admitting conduits, and providing access to the wires.
true
One great advantage of flexible metallic conduit (FMC) is its ability to absorb vibrations and allow movement, so it is often used to house wiring for pumps, motors and manufacturing equipment.
true
Rigid metal conduit (RMC) usually has the toughest and thickest walls made from coated stainless steel or aluminum, so they offer excellent protection against impacts, punctures and cuts.
true
PVC conduits are available in both Schedule 40 and 80, which are basically ratios of the thickness of the wall to its outer diameter.
false
Aluminum conduit is one type of metallic conduit.
true
Since electrical conduits are essentially a safety feature, you should select the material, size and fittings based on the environment of the installation and the type of wiring it will be housing.
true
Fittings for electrical metallic tubing (EMT) are both readily available and inexpensive.
true
Mechanical lugs are available bolted with two screws or with four screws.
true
Unshielded twisted pair cables (UTP) are more affordable than coaxial or optical fiber cables, so UTP cables are often used in telephones, security cameras and data networks.
true
Electrical nonmetallic tubing (ENT) can only be used outdoors, in areas where they will not be exposed to physical damage, hazardous conditions, temperatures over 50°C and the conductors do not carry over 600 volts.
false
The National Electrical Code and Local Building Codes regulate the manner of installation and the types of wires and cables for various electrical applications.
true
Nipples are threaded on both ends and can be installed quickly and easily.
true
Three methods of mounting circuit breakers: fixed mounted; removable mounted and drawout mounted.
true
Liquidtight flexible metallic conduit (LFMC) is durable and strong; therefore, they can be exposed to stresses or encased in concrete.
false
A Schedule 80 conduit will have a thinner wall than Schedule 40, so it is not permitted for installations where the conduit will be exposed to physical stresses.
false
Electrical metallic tubing (EMT) is light and bends easily.
true
Mechanical lugs are suitable for brass lightning protection and where there may be plenty of vibration
true
Direct-buried cables (DBCs) have high tolerance to temperature changes, moisture and other environmental factors.
true
A bushing is installed on the inside of the box opening and threaded into the conduit end, separating the conductors from the edges of both the opening and the conduit end.
true
For coaxial cable, the two inner shields share the same geometric axis.
true
Triplex wires are usually used in single-phase service drop conductors, between the power pole and weather heads.
true
The adjustable speed drive is a unified combination of devices that enable operators to drive as well as adjust the operating speed of a mechanical load.
true
RMCs are usually called ‘thinwalls’, since they have a much thinner wall than others.
false
Wire Lettering: H represents heat resistance and W represents suitable for wet locations.
true
Most connectors have two main parts: the housing and terminals for making the connections.
true
A reducer is a special kind of combination coupling that allows you to connect raceways of one trade size only to smaller ones.
false
Thermal circuit breakers use heat as a measure of current flowing through a circuit and disconnect once a certain temperature is reached, while magnetic circuit breakers rely on electromagnetic energy created by electricity to trip a switch and disconnect the power supply.
true
