What best defines resistance?

• A. How much something allows current to pass, amps.
• B. How much something opposes the passage of electrical current, ohms.
• C. The rate of electrical power, watts.
• D. The amount of charge stored, coulombs.

Answer: (B)

Resistance is a measure of how strongly a component or material opposes the flow of electric charges. It is defined by Ohm's law as R = V / I, with the unit the ohm. This means for a given voltage, a higher resistance yields less current, while a lower resistance allows more current to pass. It’s different from the amount of current (amps), the rate of power (watts), or the stored charge (coulombs). Factors like length, cross-sectional area, material, and temperature influence resistance: longer or thinner conductors have higher resistance, materials with higher resistivity resist more, and temperature changes can increase or decrease resistance depending on the material.