Which statement defines resistance?

• A. Electrical pressure pushing current
• B. Flow of electricity measured in amps
• C. Opposition to current flow
• D. Alternating current changes direction

Answer: (C)

Resistance is the property of a material or component that opposes the flow of electric current. It determines how much current will flow for a given voltage, described by Ohm’s law: V = I × R. When resistance is higher, the same voltage produces less current; when resistance is lower, more current flows. Resistance is measured in ohms (Ω). Factors that affect it include the material’s resistivity, the length and cross-sectional area of the conductor, and temperature—metallic resistance typically increases with temperature, and a longer or thinner conductor has higher resistance.

This concept contrasts with the idea of electrical pressure that pushes current (voltage), the flow of electricity itself (current), and the notion of alternating current changing direction (AC behavior). The best description of resistance is that it opposes current flow.