Heating Effect
  • Heating Effect
  • Moving charges collide with the atoms of the conductor resulting in an increase in the internal resistance of the conductor in the form of heat.
    • Factors affecting the amount of heat produced
      • The resistance (The greater the resistance the greater the heat produced)
      • The strength of the current
      • The length of time
    • Calculations of heat produced

    Since  W=QV and Q=It   : heat produced W=IVt

    Since V=IR   : W=I2Rt

    Since I = V/R  : W = V2t
                                       R

    • Everyday uses of the heating effect
      • Heating elements (e.g. Toasters, kettles, light bulbs (tungsten))
        The elements should have the following properties
        • high resistance
        • high melting point
        • not react to oxygen easily
      • Fuses – as safety precautions
        They should have the following properties
        • low resistance
        • low melting points