resistors

• describe resistance

  anything opposing electric current
• give measurements of resistance

  ohms
• describe ohmic conductor

  resistance remains constant as current changes meaning current is directly proportional to potential difference
• give examples of non ohmic conductors

  filament lamp, diode, thermistor and light dependent resistor
• describe resistance across filament lamp

  resistance increases as current increases due to increase in temperature
• describe characteristics across diode

  one direction current flow due to very high resistance in reverse direction
• describe resistance across thermistor

  resistance increases as temperature decreases

  low temp - high resistance

  high temp - low resistance
• give uses of thermistors

  thermostats
• describe resistance across light dependent resistors

  resistance increases as light intensity decrease

  low light intensity - high resistance

  high light intensity - low resistance
• give uses of light dependent resistors

  automatic night lights, outdoor lighting and burglar detectors