# \#reactance **URL:** https://scanalyst.fourmilab.ch/tag/reactance/5063.md [Latest](https://scanalyst.fourmilab.ch/latest.md) · [Categories](https://scanalyst.fourmilab.ch/categories.md) · [Tags](https://scanalyst.fourmilab.ch/tags.md) --- ## [How Does Electricity “Know” a Circuit Is Open or Closed?](https://scanalyst.fourmilab.ch/t/how-does-electricity-know-a-circuit-is-open-or-closed/4081)
**Author:** [@johnwalker](https://scanalyst.fourmilab.ch/u/johnwalker)\ **Replies:** 0\ **Last updated:** [9 December 2023 14:19 UTC](https://scanalyst.fourmilab.ch/t/how-does-electricity-know-a-circuit-is-open-or-closed/4081 "2023-12-09T14:19:01Z")
Ohm’s law only applies to electrical circuits carrying direct current at equilibrium. When current is changing, whether due to an alternating current supply or transients when a circuit is connected, reacta…