What is the basic unit of electrical resistance?

What is the basic unit of electrical resistance?

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

Answer: (C)

Resistance is measured in ohms. An ohm is defined as the resistance between two points of a conductor when a constant potential difference of one volt, applied to those points, produces a current of one ampere, with no electromotive force in the conductor. In other words, R equals V divided by I, so when you apply a voltage and observe the current, the resistance comes out in ohms (Ω). For example, if 10 volts drive 2 amperes through a component, the resistance is 5 ohms. Other units describe different quantities: volts measure electrical potential difference, amperes measure current, and siemens measure conductance (the reciprocal of resistance). So the unit that directly represents resistance is the ohm.

Resistance is measured in ohms. An ohm is defined as the resistance between two points of a conductor when a constant potential difference of one volt, applied to those points, produces a current of one ampere, with no electromotive force in the conductor. In other words, R equals V divided by I, so when you apply a voltage and observe the current, the resistance comes out in ohms (Ω). For example, if 10 volts drive 2 amperes through a component, the resistance is 5 ohms.

Other units describe different quantities: volts measure electrical potential difference, amperes measure current, and siemens measure conductance (the reciprocal of resistance). So the unit that directly represents resistance is the ohm.