[Physics] Electric field around a current carrying conductor

electromagnetism

The picture shows the direction of the magnetic field around a current carrying wire. I wonder what will be the direction of the electric field with respect to the direction of the magnetic field ? I am trying to visualize both electric and magnetic field at the same time. I am getting the picture of the direction of the magnetic field everywhere but could not find any picture that shows both of them togather.

enter image description here.

Best Answer

In a circuit involving potential drop (so, not purely a current wo/voltage,) the e-field around conductors is perpendicular and radial, and the e-field around resistors is radial with some tilt.

For conductors with arbitrarily small resistance, the flux-lines of e-field appear in the space outside the conductor, and are connecting the surface-charge with charges found upon other, distant parts of the circuit (e.g. parallel wires having opposite charge.) Here's the oversimplified visual version:

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  • Simple circuit:

    SIMPLE CIRCUIT

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  • Magnetic flux, circles around wires
    enter image description here

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  • E-field flux, radial lines connecting surface-charge enter image description here

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  • Both together: cross product is poynting flux, energy-flow from source to sink enter image description here

. Notice that the fields are those of a 2-wire waveguide or transmission line? Exactly right. The same physics applies at Zero Hz DC, and also applies at 60Hz AC, and also at radio frequencies.