Resistance of a filament lamp

• Resistor


  A component that adds resistance to a circuit
• Resistor


  • Symbol can be recognized
  • Resistance is constant if temperature is constant
• Current-potential difference graph for an ohmic conductor


  1. Plot potential difference on x-axis

  2. Plot current on y-axis

  3. Obtain a straight line passing through the origin
• Increasing potential difference across a resistor

  Increases the current flowing through the resistor
• Resistance


  Potential difference required to drive a current through a component
• Ohm


  Unit of resistance
• Resistance is calculated by dividing potential difference by current
• Resistance can be useful in circuits to control the amount of energy transferred to a component
• Resistors


  • Can have any resistance value needed
• Resistors are added in series with other components to share the potential difference
• Resistance is constant for an ohmic conductor if temperature is constant