The Unit of Resistance

The practical unit of resistance is Ohm. A conductor is said to have resistance of one ohm if it permits one ampere current to flow through it when one volt is impressed across its terminals. Ohm The symbol of ohm is shown below.

the ohm symbol

Table (multiples and submultiples of Ohm)

For insulator whose resistance are vey high, a much bigger unit is used i.e, mega-Ohm = 10^6 ohm (the prefix 'mega' or 'mego' meaning a million) or kiliohm=10^3 ohm (the prefix 'kilo' meaning thousand). in the case of vey small resistance, smaller units like miliohm = 10^-3 ohmor microohm = 10^-6 are used.

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