Which statement best defines resistance?

• A. The opposition to the flow of current in a material, measured in ohms
• B. The amount of current in a circuit
• C. The rate of energy usage
• D. The voltage across a component

Answer: (A)

Resistance is the opposition to the flow of current in a material, and it is measured in ohms. This concept explains how a component restricts electron movement when voltage is applied. According to Ohm's law, current equals voltage divided by resistance, so higher resistance for the same voltage means less current, while lower resistance means more current. The other statements describe current, power, or voltage, not the resistance itself.