Thomson effect

Thomson effect

• Thomson effect is related to the emf that develops between two parts of the single metal when they are at different temperature
  
• Thus Thomson effect is the absorption or evolution of heat along a conductor when current passes through it when one end of the conductor is hot and another is cold
  
• If two parts of the metal are at small temperature difference dT ,then the electric potential difference is proportional to dT dV α dT
  or
  dV=σdT
  where σ is the constant of proportionality and is known as Thomson coefficient
  
• Peltier coefficient and Thomson coefficient are related to thermo-power according to following relations
  π=Ts=T(dE/dT)
  and σ =-T(ds/dT)=-T(d²E/dT²)
  
• We have seen that all the three effects are defined in terms of three coefficient namely Seaback,Peltier and Thomson coefficient but the basic quantity is thermo-power which is the rate of change of thermo-emf with temperature

• Notes
  • Heating effect of current
  • Thermoelectricity
  • Seebeck effect
  • variation of thermo-emf with temperature
  • Peltier Effect
  • Thomson effect