Current electricity (AQA A-Level Physics): Flashcards
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Definition of resistivity
Definition of resistivity
Property measuring how well a material conducts electricity
Formula for resistivity ()
Formula for resistivity ()
Effect of temp. on metal conductor resistance
Effect of temp. on metal conductor resistance
Resistance increases as temperature rises
Mechanism: metal resistance increase with temp.
Mechanism: metal resistance increase with temp.
Atoms vibrate more, more collisions, slower electron flow
Effect of temp. on thermistor resistance
Effect of temp. on thermistor resistance
Resistance decreases as temperature increases
Application of thermistors
Application of thermistors
Temperature sensors in circuits (control heaters/fans)
Definition of superconductor
Definition of superconductor
Material with zero resistivity below critical temp.
Critical temp. of superconductors (approx.)
Critical temp. of superconductors (approx.)
Close to absolute zero (-273°C)
Superconductor use: power cables
Superconductor use: power cables
Transmit electricity with no energy lost to heat
Superconductor use: maglev trains
Superconductor use: maglev trains
Generate magnetic fields for frictionless motion