Electric current Flashcards
Charge carriers
Charged particles that move through a substance when a pd is applied across it
Potential difference
Work done or energy transfer per unit charge between two points when charge moves from one point to the other
Critical temperature
Temperature at and below which a superconducting material’s resistivity is zero
Superconductor
A material with zero electrical resistance at and below its critical temperature
Positive temperature coefficient
The resistance of a semiconductor increases when its temperature is increased
Negative temperature coefficient
The resistance of a semiconductor decreases when its temperature is increased
Ohm’s law
The pd across a metallic conductor is proportional to the current, provided the physical conditions don’t change
Potential divider
Two or more resistors in series connected to a source of pd
Power
Rate of transfer of energy
Resistivity
Resistance per unit length x area of cross-section
Semiconductor
A substance in which the number of charge carriers increases when the temperature is raised
