c) Fixed resistors/lamps

ci) I-V characteristics of resistor, filament lamp, thermistor, diode, and light-emitting diode (LED)

fixed resistor (regardless of the polarity)

• current → directly proportional to potential difference

• resistance = constant

• ohmic conductor

filament lamp (regardless of the polarity)

• current → not directly proportional to potential difference

• resistance = increasing

  • more electrons → more collisions with positive ions → electrons and positive ions have more kinetic energy

• non-ohmic conductor