Chapter 4 - Fundamentals Of Electricity, Magnetism, And Electronics Flashcards
Alternating current (AC)
Electric current that alternately changes direction.
Ammeter
An instrument for measuring the flow of electric current.
Ampere (A)
A unit of measurement for flow of electric current.
Atom
The smallest particle of an element that can exist, alone or in combination.
Base
One of the three elements in a transistor.
Bound electron
A closely held electron that never leaves an atom.
Circuit breaker
A switch that trips to the open position to stop excess current flow in a circuit. After a breaker trips, it can be reset to allow current flow through the circuit.
Collector
One of the three elements in a transistor.
Conductors
A material along or through which electricity will flow with slight resistance; silver, copper, and carbon are good conductors.
Direct current (DC)
Electric current that flows continuously in one direction, such as that generated by a storage battery.
Domain
A group of atoms having the same magnetic polarity.
Electronic
Term used to describe any electrical component, assembly, circuit, or system that uses semiconductor, or solid state, devices.
Electron
Negatively (-) charged particle that travels in orbit around the center of the atom.
Emitter
One of the three elements in a transistor.
Forward biased
Term used to describe a diode that is connected in a circuit in such a way that it acts as a conductor.
Free electron
An electron that can be freed to move from one atom to another when electricity is applied.
Fuse
Circuit protection device that contains an internal conductor that is designed to melt when current in the circuit exceeds the current rating of the fuse.
Fusible link
A special type of wire that is designed to melt when too much current is flowing through a circuit. This type of circuit protection device is generally used in circuits that carry large amounts of current.
Insulator
A nonconductor of electricity. Material in which the majority of atoms contain bound electrons. Can also refer to the aluminum-oxide ceramic material that surrounds a spark plug’s center electrode and forms top portion of the spark plug.
Jumper wire
A length of wire with alligator clips at each end used to bypass components or to apply source voltage directly to a component.
Magnetic field
Force produced by a magnet and evidenced by lines of force, or magnetic flux, around the magnet.
Multimeter
A measuring instrument that is a combination ammeter, ohmmeter, and voltmeter.
Neutron
An electrically neutral particle found in the nucleus of an atom.
Ohmmeter
An instrument that measures the resistance to the flow of electrical current through a conductor.
Ohm
A measurement of the resistance to the flow of an electrical current through a conductor.
Ohm’s law
Formula used to calculate an unknown circuit value when two other values are known.
Parallel circuit
An electrical circuit in which there is more than one path for the current to flow.
Peak inverse voltage (PIV)
The amount of voltage a diode can take in the reverse direction without being damaged.
Proton
A large, heavy, positively (+) charged particle found in the nucleus of an atom.
Relay
A device used as an electrical switch, allowing a relatively low current to be used to control a high current.
Reverse biased
A term used to describe a diode that is connected in a circuit in such a way that it acts as an insulator.
Semiconductor diode
A two-element solid state electronic device that permits current to flow in only one direction.
Semiconductor material
A material that can act as a conductor under certain conditions and and insulator under other conditions. Common semiconductor materials include silicon, germanium, and selenium.
Series circuit
Electrical circuit in which the current passes from the power source to each device in turn and then flows back to other terminal of the battery.
Series-parallel circuit
Electrical circuit in which some electrical devices are connected in series and other are in parallel.
Silicon-controlled rectifier
A semiconductor component that conducts electricity only when dc voltage is applied to its gate.
Solenoid
An iron core, surrounded by a coil of wire, that moves due to magnetic attraction when an electrical current is fed to the coil. Solenoids are often used to actuate mechanisms by electrical means.
Solid-state device
A term used to describe electrical devices that have no moving parts. These devices are made from semiconductor materials.
Switch
A device used to control the flow of current in an electrical circuit.
Test light
A diagnostic tool used to check for continuity or the presence of voltage in an electrical circuit.
Transformer
An electrical device designed to increase or decrease voltage or current levels.
Transistor
A semiconductor device that is often used for switching applications.
Volt (V)
A unit of electrical force that will cause a current of one ampere to flow through a resistance of one ohm.
Voltmeter
An instrument for measuring the voltage in an electrical circuit.
