If cross-sectional area increases, resistance in a conductor will?

• A. Increases
• B. Decreases
• C. Stays the same
• D. Doubles

Answer: (B)

Resistance decreases when cross-sectional area increases. The relationship is given by R = ρL/A, where ρ is resistivity, L is length, and A is cross-sectional area. With area growing while length and material stay the same, resistance goes down because there are more pathways for electrons to move and the current can flow with less opposition. In practical terms, doubling the cross-sectional area roughly halves the resistance.

This is why thicker wires have lower resistance and smaller voltage drops over the same length. Temperature and material still matter, since resistivity can rise with temperature, but the effect of increasing area is always to reduce resistance under fixed conditions.