Ohm Ω
About the Ohm
The ohm is the resistance that passes a current of one ampere under a potential difference of one volt. It is named after Georg Ohm, whose law relates voltage, current and resistance. The quantum Hall effect provides the modern practical standard.
Related Units
Coulomb
C1 C = 1 A·s
The coulomb is the charge carried by a current of one ampere in one second. Since 2019 one coulomb is exactly...
Volt
V1 V = 1 W/A = 1 kg·m²·s⁻³·A⁻¹
A volt is the potential difference across a conductor when a current of one ampere dissipates one watt. It is named...
Siemens
S1 S = 1 Ω⁻¹ = 1 kg⁻¹·m⁻²·s³·A²
The siemens measures conductance, the reciprocal of resistance, and replaced the informal mho (ohm spelled backwards)...
Farad
F1 F = 1 C/V = 1 kg⁻¹·m⁻²·s⁴·A²
A capacitor of one farad stores one coulomb of charge at a potential difference of one volt. The unit honours Michael...