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Suppose a resistor is connected on both sides to a copper wire, in a simple circuit with a battery. Resistor and wires are cylinders of equal diameter. A DC current is flowing through the resistor and the wires. The current is axial everywhere, and the electric field is also axial. The strength of the electric field is constant in the resistor, E = U/d (U is voltage, d is length of the resistor), and it is close to zero in the copper wires.

This E field seems to be similar to the E field of a parallel plate capacitor. The two boundary surfaces S

This E field seems to be similar to the E field of a parallel plate capacitor. The two boundary surfaces S

_{1}and S_{2}between copper and resistor are the source and the sink of the E field. Is it correct to conclude that the boundary surfaces S_{1}and S_{2}carry a surface charge Q = U/C, where C = A ε_{x}/d , and that the resistor behaves like a capacitor for AC frequencies ω > 1/RC ?
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