Potential difference

• Potential difference (voltage)


  A measure of the amount of energy given to the charge carriers (electrons) in a circuit

  
• E = QV


  The equation linking energy transferred, charge flow and potential difference

  
• E


  The symbol for energy transferred
• Q


  The symbol for charge flow
• V


  The symbol for potential difference
• Joules (J)


  The SI unit for energy and work

  
• Coulombs (C)


  The SI unit for charge flow

  
• Volts (V)


  The SI unit for potential difference

  
• 1 volt is equal to

  The potential difference when one coulomb of charge transfers one joule of energy (1 V = 1 J/C)

  
• V = IR

  The equation linking potential difference, current and resistance; also known as Ohm's Law

  
• Current


  The rate of flow of electric charge (electrons) around a circuit

  
• Resistance


  The opposition to the movement of electric current through a material

  
• I


  The symbol for current
• R


  The symbol for resistance
• Amps/amperes (A)


  The SI unit for current

  
• Ohms (Ω)


  The SI unit for resistance