In the International System of Units (SI), the **ohm** is the unit of electrical resistance. It is denoted by the symbol **Ω**.
One ohm is defined as the resistance between two points of a conductor when a constant potential difference of one volt is applied to these points and the resulting current is one ampere. This relationship can be expressed by Ohm's Law:
\[ R = \frac{V}{I} \]
where \( R \) is resistance in ohms, \( V \) is voltage in volts, and \( I \) is current in amperes.
In terms of fundamental SI units, an ohm can be expressed as:
\[ 1 \, \Omega = 1 \, \text{V/A} \]
where \( \text{V} \) is volts and \( \text{A} \) is amperes. It can also be broken down into base units:
\[ 1 \, \Omega = \frac{1 \, \text{kg} \cdot \text{m}^2}{\text{s}^3 \cdot \text{A}^2} \]
where \( \text{kg} \) is kilograms, \( \text{m} \) is meters, \( \text{s} \) is seconds, and \( \text{A} \) is amperes.