39 terms

drift velocity

term for the average velocity of an electron in the direction of current

resistance

term for the voltage required to produce a unit of current

ohmic

term that describes conductors whose resistance remains constant over a wide range of voltages

nonohmic

term that desribes conductors that fail to display constant resistance over a a wide range of voltages

length

The resistance of a conductor is directly proportional to its ____.

cross-sectional area

The resistance of a conductor is inversely proportional to its ______ ____.

resistivity

term for the constant of proportionality in the resistance equations

rheostat

term for an adjustable resistor that is used wherever it is desirable to have manual control of the resistance in a circuit

conductor

term for a material that allows relatively free flow of electrons

insulators

term for materials composed of atoms that hold tightly to their electrons and are poorly suited to conduct a current

semiconductors

term for materials with intermediate values of resistivity

superconductive

When a material's resistivity drops to zero, the material becomes ______.

circuit

term for a pathway for current

current source (battery)

term for the part of a circuit that boosts the energy of a charge before sending it out at one terminal

conductors

term for the parts of a circuit that provide the pathway between the battery and the load

load

term for the part of a circuit that uses the charge's energy to do some type of work

Conventional current

_____ ____ treats electricity as a movement of positive charge from a positively charged region to a negatively charged region.

Ohm's law

term for the equation V = IR

voltage

term for the potential added to a positive charge moving through a battery

IR drop

term for the product IR, which specifies the potential drop over a pure resistance R carrying a current I

equivalent resistance

term for a single resistance with the same effect as other resistances in combination

series

If one resistor follows another directly so that current can follow only one pathway through both resistors, they are called ____ resistors.

parallel

If the current follows different pathways through the resistors, they are ____ resistors.

network

term for a circuit that contains any combination of series and parallel resistors

internal resistance

term for resistance within a battery

open circuit

term for a circuit which does not permit current because its resistance is essentially infinite

open-circuit voltage

The voltage listed on a battery is sometimes referred to as its _____ ____.

closed circuit

If R has a finite value other than zero, a circuit is described as a(n) ____ ____.

closed-circuit voltage

term for the voltage between terminals (the difference between the voltage supplied by a battery and the quantity IR)

short circuit

term for conducting wires with no loads and almost zero resistance

multimeter

term for a single device that contains an ammeter, voltmeter, and ohmmeter

galvanometer

term for a meter that measures small amounts of current

ammeter

term for a meter that measures the current through a resistor in the circuit's branch

voltmeter

term for a meter that measures the voltage (IR drop) across a resistor

ohmmeter

term for a meter that measures the resistance of a resistor

junctions

term for the points where the current diverges or converges

principle of charge conservation

the principle that states that charge can neither be created nor destroyed

Kirchhoff's first law

tha law that states that, at any circuit junction, the incoming current must equal the outgoing current

Kirchhoff's second law

the law that states that the sum of all the voltages around a full circuit must equal zero