Power, Current and Voltage

• Power, Current and Voltage

  • Electrical power: The rate at which an appliance transfers energy
  • Appliances that have a high power will transfer lots of energy in a short period of time
  • Measured in Watts (W)

  P = IV P = Power (W)

  I = P/V I = Current (A)

  V = P/I V= Voltage (V)

  A) P (W)

  B) I (a)

  C) V (V)

  
• Fuses and Current Ratings

  • The current rating is the maximum current the fuse can carry without blowing
  • In order to operate as efficiently as possible, the fuse should be rated just above the operating current of the circuit
• Energy Transferred

  • Energy is transferred by an appliance into a variety of other useful forms
  • Measured in Joules (J)

  E = IVt E = Energy transferred (J)

  I = Current (A)

  V = Voltage (V)

  t = time (s)

  A) E (J)

  B) I (a)

  C) V (V)

  D) t (s)