What is the unit of electrical resistance?

• A. Ampere
• B. Volt
• C. Ohm
• D. Watt

Answer: (C)

Resistance is the property that opposes the flow of electric current. According to Ohm’s law, resistance equals voltage divided by current (R = V / I). Since voltage is measured in volts and current in amperes, the unit of resistance is volts per ampere, defined as one ohm. The symbol for the ohm is the Greek letter omega (Ω). Other options represent different electrical quantities: ampere is current, volt is voltage, and watt is power, not resistance.