What Is Ohm's Law?

Ohm's law states that the current through an ohmic conductor is proportional to the voltage across it: V = I R. The constant of proportionality, R, is the resistance, measured in ohms (Ω).

For an ohmic material, R does not depend on V or I. Examples: most metallic resistors over a wide range. Non-ohmic devices include diodes (exponential I–V), filament bulbs (R rises with T), thermistors, and plasmas.

Microscopic Ohm's law: J = σE, with current density J, conductivity σ, and electric field E. Resistance R = ρL/A then follows from geometry, where ρ = 1/σ is the resistivity.

Recent research on this topic from arXiv

Preprints and papers indexed on arXiv.org. Links open the public abstract pages.

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