resitance

• Resistance


  The potential difference required to drive a current through a component
• Energy transfer in an electric circuit

  1. Cell contains chemical energy

  2. Chemical energy transferred to electrical energy

  3. Electrical energy carried by current

  4. Electrical energy transferred to other forms of energy (e.g. light, thermal) in components
• Potential difference across a component


  Indicates the amount of electrical energy transferred to other forms of energy in that component
• Resistance


  • Determines the potential difference required to drive a current through a component
  • Indicates how much energy is required to push a coulomb of charge through a component
• Lamps with different resistance

  • Lamp A (low resistance): 1V potential difference, 1A current
  • Lamp B (high resistance): 10V potential difference, 1A current
• Resistance equation


  Resistance (Ω) = Potential difference (V) / Current (A)
• Calculating resistance


  Plug current and potential difference values into resistance equation
• Calculating potential difference


  Potential difference (V) = Current (A) x Resistance (Ω)