d) Diode/LED/LDR

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

d) light-dependent resistor (LDR); variation of resistance with light intensity

diode/LED

for a positive current and potential difference
- current is not proportional to potential difference
  - it is a non-ohmic conductor
- resistance is decreasing
for a negative current and potential difference
- current is not proportional to potential difference
  - it is a non-ohmic conductor
- resistance is infinite

for an LDR