A cylindrical Gaussian surface encloses a long straight wire carrying a current.

A cylindrical Gaussian surface encloses a long straight wire carrying a current. What is the electric field at a distance r from the wire?

A cylindrical Gaussian surface encloses a long straight wire carrying a current. What is the electric field at a distance r from the wire?

Step 1: Understand that we are dealing with a long straight wire that carries an electric current.
Step 2: Recognize that the electric field around a current-carrying wire is not the same as the magnetic field.
Step 3: Remember that Gauss's law is used to calculate electric fields, but it is not applicable for the electric field around a current-carrying wire.
Step 4: Conclude that the electric field at a distance r from the wire is not defined by Gauss's law.

Gauss's Law – A principle that relates the electric flux through a closed surface to the charge enclosed by that surface.
Electric Field vs. Magnetic Field – Understanding the distinction between electric fields produced by static charges and magnetic fields produced by moving charges (currents).
Cylindrical Symmetry – The symmetry of the problem allows for simplifications in calculating electric or magnetic fields around cylindrical objects.