Explanation: The resistance of a conductor is inversely proportional to its cross-sectional area. This means that if the area decreases, the resistance increases proportionally, and vice-versa. Imagine a conductor as a pipe carrying water (current). If you make the pipe narrower (reduce its cross-sectional area), it becomes harder for the water to flow through, increasing the "resistance" to flow. Mathematically, resistance $R = \rho \times (L/A)$, where $\rho$ is resistivity, $L$ is length, and $A$ is the cross-sectional area. If $A$ is halved, the denominator becomes half its original value, effectively doubling the resistance. Therefore, halving the cross-sectional area of a conductor will double its resistance.