Current In A Short Circuit [updated] Jun 2026

However, the power grid is a different beast. The internal resistance of a municipal power grid is infinitesimally small. When a short circuit occurs in a home or industrial setting, the grid can deliver an immense amount of current—often thousands or tens of thousands of amperes. This brings us to the destructive potential of the short circuit.

In a theoretical scenario known as an "ideal short circuit," the resistance ($R$) approaches zero. Mathematically, as resistance approaches zero, the denominator in Ohm’s Law shrinks, causing the current ($I$) to approach infinity ($\infty$). If a voltage source of 12 volts were connected across a resistance of 0 ohms, the resulting current would theoretically be infinite. This exponential surge is the fundamental nature of a short circuit—a desperate, massive rush of electrons seeking to equalize potential difference through the easiest available path. current in a short circuit