The correct option is Ohm.
Explanation
Electrical resistance is a physical quantity that measures the opposition offered by a material to the flow of electric current. The International System of Units (SI) assigns specific derived units to electrical quantities to ensure global standardization in scientific measurement.Option Analysis
- Ohm Ohm: Correct. The SI unit of electrical resistance is the Ohm, denoted by the Greek letter Omega (Ω). It is defined based on Ohm's Law: one Ohm is the resistance of a conductor such that a potential difference of one volt across it causes a current of one ampere to flow ($1\Omega = 1V/1A$).
- Watt Watt: Incorrect. The Watt (W) is the SI unit of power, representing the rate at which energy is consumed or produced.
- Henry Henry: Incorrect. The Henry (H) is the SI unit of inductance.
- Weber Weber: Incorrect. The Weber (Wb) is the SI unit of magnetic flux.
Key Takeaway
The SI unit of electrical resistance is the Ohm (Ω). It should not be confused with units for power (Watt), inductance (Henry), or magnetic flux (Weber).