# Why electric field is zero inside a conductor?

 P: 886 Ohm's law (differential form) $\textbf{j}=\sigma\textbf{E}$ If E is not zero, then a current will very quickly form in a conductor. If the conductor is surrounded by insulator, then charge can't escape from the conductor, so you can't have net current escaping from the conductor. Therefore, the flux of E over the surface of the conductor is 0. There's no law that says E is zero inside the conductor, but it goes to 0 very quickly in steady state or slowly varying conditions. Internal E field will generate internal currents, which will quickly dissipate electrical energy into heat via internal resistance.