Recently I read in the basic EM theory course , that the Ohmic power dissipated in a conductor is directly proportional to the conductivity and the square of the electric field intensity , but we know perfect conductors (conductivity=inf) dissipate zero power , isn't this contradictory , also formula is given on Page 391 , Alexander Sadiku ,EM Theory , thanks.

  • \$\begingroup\$ Didn't you think that including the formula you're asking about in your question would make sense? \$\endgroup\$ – Dmitry Grigoryev Aug 16 '18 at 13:09

A Perfect conductor has zero (steady state) electric field across it by definition, otherwise infinite current would flow.

The statement above is just P=V^2/R generalised to a unknown conductor geometry and written in terms of conductivity and field strength rather then resistance and applied terminal voltage.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.