Electrical Theory
This is the unit used to measure electrical resistance.
What is an ohm?
This tool is used to measure voltage, current, and resistance in electrical circuits.
What is a Multimeter?
This is the standard voltage supplied to most outlets in North American homes.
What is 120 Volts?
This component disconnects power to the entire home when turned off.
What is the main breaker?
This must always be done before working on any electrical circuit.
What is turn off the power (or de-energize the circuit)?
This unit measures the electrical potential difference between two points in a circuit.
What is a Volt?
Electricians use this type of pliers to twist wires together and cut wire ends.
What are lineman's pliers?
This safety device shuts off power when it detects current leaking to ground.
What is a GFCI?
This wire color is typically used to indicate a “hot” or live wire in residential circuits.
What is black (or red)?
This common household device will trip to stop current flow when a circuit is overloaded.
What is a circuit breaker?
In Ohm’s Law, this letter represents current, which equals voltage divided by resistance.
What is I?
This metal is most commonly used as the conductor in residential wiring.
What is copper?
In this type of circuit, devices are connected along multiple paths so each has its own loop.
What is a parallel circuit?
The NEC requires at least this many inches of free conductor at each outlet or junction box.
What is 6 inches?
This device can detect the presence of voltage without making contact.
What is a non-contact voltage tester?
This type of current changes direction periodically and is used in most homes.
Answer: What is alternating current?
What is alternating current?
In residential wiring, this color typically identifies the ground wire.
What is green or bare?
This size wire is typically used for a 15-amp residential lighting circuit.
What is 14-gauge wire?
This small plastic device is twisted onto wire connections to hold them securely and insulate them.
What is a wire nut?
When a switch doesn’t turn on a light, checking this component in the fixture is a good first step.
What is the light bulb (or lamp)?
This is the term for the rate at which electrical energy is consumed or transferred in a circuit.
What is power?
This type of screwdriver fits slotted screw heads and is common in electrical work.
What is a flathead screwdriver?
This term describes a circuit that has been interrupted and no longer allows current to flow.
What is an open circuit?
These interrupters are now required in living areas to protect against arc faults.
What are AFCIs?
This is a dangerous condition where the hot wire touches a neutral or ground, causing high current flow.
What is a short circuit?