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ohm

/oʊm/
IPA guide

Other forms: ohms

An ohm is a unit of electricity — or more specifically, a unit of electrical resistance. The resistance of good electrical conductors, like copper, is measured in ohms.

When it comes to electricity, there are many ways to measure it, including amps of current and volts of voltage. Ohms specifically measure the amount of resistance in an electrical current, an idea that's easiest to understand in terms of plumbing. Picture water flowing through a pipe; the water pressure is the voltage, the rate at which it flows is the current, and the size of the pipe is the resistance. Ohm is named for Georg S. Ohm, the physicist who discovered the relationship between current, voltage, and resistance.

Definitions of ohm
  1. noun
    a unit of electrical resistance equal to the resistance between two points on a conductor when a potential difference of one volt between them produces a current of one ampere
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    type of:
    resistance unit
    the reciprocal of conductance
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