Resistance

• Resistance


  One of the most important equations in electronics, linking potential difference, current and resistance
• Ohmic conductors


  • Resistance doesn't change with current at constant temperature
  • Current is directly proportional to potential difference
• Non-ohmic conductors


  • Resistance changes with current, e.g. filament lamp, diode
  • Resistance increases with temperature for filament lamp
  • Resistance depends on direction of current for diode
• Resistance is directly proportional to wire length
• If graph doesn't go through origin, it's a systematic error due to first clip not being at 0 cm