Definition:Ohm (Unit)

Definition

The ohm is the SI unit of electrical resistance.

It is defined as being the electrical resistance between two points of an electrical conductor when a constant electric potential of $1$ volt, applied to these points, produces in the conductor an electric current of $1$ ampere, the conductor not being the seat of any electromotive force.

Symbol

$\Omega$

The symbol for the ohm is $\Omega$.

Its $\LaTeX$ code is \Omega .

Base Units

The SI base units of the ohm are:

$\Omega := \mathrm {kg} \, \mathrm m^2 \mathrm s^{-3} \mathrm A^{-2}$

where:

$\mathrm {kg}$ denotes kilograms

$\mathrm m$ denotes metres

$\mathrm s$ denotes seconds (of time).

$\mathrm A$ denotes ampere.

Source of Name

This entry was named for Georg Simon Ohm.

Sources

• 1969: J.C. Anderson, D.M. Hum, B.G. Neal and J.H. Whitelaw: Data and Formulae for Engineering Students (2nd ed.) ... (previous) ... (next): $1.$ Units and Abbreviations: $1.2$ SI units $(2)$ Derived units
• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): ohm
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): ohm