Chapter 10 Terms Flashcards
Stationary electrical charges
Static electricity
The force between electrical charges.
Electrostatic force
Like charges repel; unlike charges attract (opposites attract).
Law of charges
An inclination to attract or associate.
Affinity
The SI unit for electrical charge.
Coulomb (KOO lohm)
Lines used to show direction of a force exerted on an object.
Lines of force
The creation of a charged region on a neutral object when exposed to a nearby electrical charge.
Electrical induction
A neutral molecule whose electrons have shifted to form positive & negative ends, or poles (dipoles di = two, poles…well, poles)
Dipole
An instrument that can detect electrical charges.
Electroscope
Materials that offer little resistance to electrical motion (metals like copper, silver, aluminum, gold)
Electrical conductors
Materials that do NOT allow electrons to move easily (glass, wood & rubber)
Electical insulators
Materials that allow limited electron flow or conduct only under certain conditions (silicon and germanium)
Semiconductors
The loss of static charge as electrons move to another object.
Electrical discharge
A device used to protect buildings from lightning strikes.
Lightning rod
A means of storing a strong electrical charge (Invented by Pieter van Musschenbroek)
Leyden jar
Modern charge storing devices.
Capacitors
Electricity that involves continuously moving charges.
Electrical current
Old computer monitors or TVs that used vacuum tube screens that displayed images “painted” by electrons.
Cathode-ray tube (CRT)
Electrons waiting to flow from a point of higher potential in a conductor to a lower potential.
Electrical potential energy
The flow of positive charges through a conductor, which is the OPPOSITE of the flow of electrons.
Conventional current
Current that flows in one direction through a conductor. (Cell phone, digital camera are powered by this)
Direct current (DC)
A complete path from a source of electrons through a conductor and back to an electron sink.
Electrical circuit
Something that converts electricity to some other form of energy (e.g. light bulb).
Electrical load
A device that allows you to open or close a circuit by opening or closing a gap in the current path.
Switch
Device that consists of one or more electrochemical cells that supply electrons released by a chemical reaction.
Battery
Device capable of supplying electrons released by a chemical reaction.
Electrochemical cells
Unit used to measure potential difference of electrical potential.
Volt (V)
Unit used to measure electrical current (also known as Amps).
Ampere (A)
The property of a component in a circuit that hinders (slows) the flow of charges to some extent.
Electrical resistance
Special device that can change the voltage within portions of a circuit.
Resistor
Current (I) = Voltage source (V) / Resistance (R) i=v/r
Ohm’s law
Unit to measure electrical resistance.
Ohm
Unit used to dispense and bill electrical energy (energy = power * time interval).
Kilowatt-hours (kWh)
Electrical loads (e.g. light bulbs) connected one after another in the circuit path.
Series circuit
Electrical loads (e.g. light bulbs) connected in separate branches of the circuit.
Parallel circuit
Two wires that touch which makes a shortcut of the path of the circuit.
Short circuit
Ability to prevent currents in faulty circuits from starting fires.
Overcurrent protection
A switch that is manually closed but will automatically trip open if the current gets too high.
Circuit breakers
Circuit breaker that detects very high, short-duration currents caused by arcing.
Arc-fault circuit interrupt (AFCI)
Metal & glass container with a thin strip of metal inside that allows current to flow from the supply to the load.
Fuses
Device that monitors voltages between wires supplying an appliance or outlet.(GFCI)
Ground-fault circuit interrupters
