EESE Online Training Courses

 Electrical and Electronics eLearning

Click to go to the PLC Training Home Page
  Click for Electrical Subjects Click for Electronics Subjects Click to Contact Us

NUE 052 - Resistance, Ohms Law and Power Dissipation

  • Resistance is the opposition to current flow in a conductor, measured in Ohms. The symbol is R
  • A good conductor such as copper has a low resistance
  • A good insulator such as mica has a high resistance
  • Ohms law is named after George Simon Ohm who presented his laws back in 1827
  • In his honour the unit of electrical resistance was named the 'ohm'
  • Ohms law relates voltage, current and resistance
  • Power is the rate that energy is used or dissipated, measured in Watts, the symbol is P

  • Use Ohms law to find a value - cover ONE symbol in the triangle to solve the formula

    Terms used with voltage, current and resistance
    Quantity
    Abbreviation
    Measurement
    Symbol
    EMF
    E
    volt
    V
    Voltage
    V
    volt
    V
    Current
    I
    ampere
    A
    Resistance
    R
    ohm
     You can download an Ohms law calculator here for a bit of fun (for PC or MAC only)
    Practice Tests are available on the practice test page  
    Return to EESE home page