Key units and symbols

• Symbol for current

  I
• Symbol for charge

  Q
• Units for current

  Amps (A)
• Units for charge


  Coulombs (C)
• Symbol for time


  t
• Units for time

  seconds(s)
• Symbol for potential difference/voltage

  V
• Units for potential difference/voltage

  Volts (V)
• Symbol for resistance

  R
• Units for resistance

  Ohms (Ω)
• Symbol for power

  P
• Units for power


  Watts (W)
• Symbol for energy

  E
• Units for energy


  Joules (J)
• Define current

  Rate of flow of charge
• Define charge

  Fundamental quality, responsible for electrostatic attraction/repulsion.
• Equation for current, charge and time:


  $I=$$Q/t$