unit 30 electrical safety quiz

Electricity needs a path to flow through. Substances such as metals offer very little resistance to electric current flow and are called ___.

Conductors

____ resists the flow of electricity, and this is why electrical wires are not bare but instead enclosed by insulation that has a high resistance to electricity flow.

Insulation

Current is measured in ___.

Amperes

The amount of _______ that passes through a body determines the severity of an electrical shock.

current in amperes

In an ____, the electricity will flow from the source through one wire (hot conductor) connected to the load and then back again to make a closed loop or closed circuit.

electrical circuit

If you touch a live wire, then you can become part of the ___ and the electricity can flow through you.

circuit

Electricity can flow between parts of your body or through your entire body to the ground, leading to ______.

burns, electrical shock, death

An _______ can be produced when there is a short circuit or poor electrical contact between conductors such as a circuit breaker, switchgear, or air-insulated bus bars.

electric arc

An electric arc is a sudden unexpected _______ that travels through the air between conductors or from a conductor to the ground.

electric discharge

During a flash, _______ are produced.

extremely high temperatures

Intense heat during a flash leads to a sudden expansion and blast of _______ that can propel droplets of molten metal at high speeds for distances up to 10 feet.

high pressure air

You could suffer serious _______ or even be killed while not having any physical contact with the conductor/

third-degree burns

You only need to be ___ the point of the arc flash to be hurt.

near

It is important to ensure that your tools are properly ____.

grounded

Grounded means ________.

That the plug on the tool should have three prongs.

A faulty portable electric drill may have an ________ that would provide an electrical shock when turned on.

uninsulated metal casing

A ground wire from the three-prong plug will direct the _____ to the ground rather than through the person holding the drill.

stray current

Always use a _______ receptacle to plug into if available.

ground fault circuit interrupter (GFCI)

A GFCI can interrupt the flow of electricity in as little as ____ to prevent electrocution

1/40th of a second

A GFCI ____ the amount of current going into the electric device with the amount of current returning from it, and if the difference exceeds 5 milliamperes, the device automatically shuts down.

compares

Generally, to ___ a breaker you will push it into the off position, and you should hear a slight click and then push it back into the on position and you will again hear it click it as it snaps closed.

reset

Typical molded-case circuit breakers are rated with a current-carrying capacity also referred to as an _______. If a circuit is subjected to a current above its ampere rating, it will open and de-energize the circuit.

ampere rating

A motor that runs hot for a prolonged period may experience _______. This can lead to a short, where the electricity bypasses its normal path of flow. It is a “shortcut” for the electricity, and this allows for more electricity to flow (current increases). The wires in the circuit will not be large enough to carry this extra current, and they can overheat, melt, and cause a fire. Before this happens. the circuit breaker will trip.

insulation breakdown

GFCI breakers are often used for equipment to be located outdoors in damp or wet locations. GFCI breakers are used to ________. A GFCI breaker monitors the current on both sides of the circuit. If it senses more current on either side, it knows there is a ground fault and trips.

prevent electrical shock

When working in a residential setting, the first step before beginning any electrical work is to _______. Any other safety switched between the service panel and the component to be serviced should also be shut off. You want to be 100% positive that the customer or anyone else working in the area will not turn the power back on to the circuit while you are working on it.

turn off the power to the circuit at the service entrance panel.

The customer should be informed that you are working on the circuit and _______. You should attach a tag that includes your name, your company, why you have the breaker locked out, and the date. In the event that you do not finish the work and do not return to the residence, this provides information on who shut the power off and when it was secured.

the breaker should be physically locked out

As a safety precaution, the only person who may remove a lock or tag is _______. In some instances, there may be multiple locks and multiple tags on one circuit breaker. The circuit cannot be energized until all tags and locks are removed by the individuals who placed them there.

the person who placed it there.

Digital meters are very ___, so the reading may show something slightly high or lower than the expected reading.

precise

___________ do not require physical contact with the live, current-carrying conductors.

Noncontact voltage testers

______ is widely used for branch circuits and feeders in residential and commercial systems. NM cable is flame retardant and moisture resistant but suitable for dry locations only.

Nonmetallic sheathed cable

Although in some cases 14-gauge wire may be suitable for residential lighting circuits, 12-gauge wire is thicker and harder to work with, but using a wire that is _______ can lead to overheating and potentially fire. Receptacles will draw more current than lights; therefore, it is often advisable to use the larger-diameter 12-gauge wire even if it is more difficult to work with.

too small in diameter