If the length of a potentiometer wire is doubled, the accuracy in determining the null point _.

Explanation

Option A is correct: Doubling the length of the potentiometer wire enhances the accuracy in determining the null point. The longer wire provides a greater range for the sliding contact (jockey) to move, allowing for more precise measurement and better resolution. This makes it easier to detect the exact point where the potential difference is zero.Options B, C, and D are incorrect: Increasing the length of the wire does not decrease or leave the accuracy unchanged, nor does it unpredictably change. The increased length consistently improves measurement precision, making these options inaccurate.