FormulaProved

Ohm's law

Statement

I = U/R, the current I through a circuit segment is proportional to the voltage U and inversely proportional to its resistance R.

Why is it true?

Resistance R is a constant characterizing the material and shape of the conductor (for 'Ohmic' materials), independent of U or I.

A DC circuit with a source and rheostat: vary U and R, read I, and watch electrons flow — the U–I characteristic is always a line through the origin.

Stated by

Topics that use this theorem

Step-by-step proofs

No step-by-step proof yet for this theorem.

References