发表机构
School of Science, Huzhou Normal University; School of Intelligent Manufacturing, Huzhou University（湖州师范学院理学院; 湖州学院智能制造学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究用细铜棒探测亥姆霍兹线圈交变磁场，测量感应电动势随径向位置的变化，构建四种简化模型定量解释实验现象，并验证了极值点位置与变化趋势。
AI 中文摘要
我们采用一根细金属棒（铜棒）作为探针，置于亥姆霍兹线圈产生的交变磁场中，测量了金属棒在亥姆霍兹线圈不同径向位置处感应电动势的变化。实验结果表明，当金属棒中心穿过亥姆霍兹线圈内部圆柱形磁场的中心时，感应电动势为零。当金属棒从磁场中心移至不同径向位置时，感应电动势从零逐渐增大，在某一位置达到最大值，随后随着径向距离的继续增加而单调减小。在感应电动势达到最大值的位置，金属棒与亥姆霍兹线圈内部磁场的径向截面相交于两点，金属棒的中央小部分位于亥姆霍兹线圈内部，而两端部分位于线圈外部。为解释实验现象，我们基于亥姆霍兹线圈的实际磁场分布构建了四种简化的磁场分布模型，以定量研究沿金属棒的感应电动势的径向变化。我们的理论结果表明，四种模型得出的结果相似，均能定性解释实验数据曲线，尤其能很好地再现感应电动势的变化趋势及极值点的位置。分段函数拟合模型的结果与实验数据在定量上吻合良好。这项工作对本科阶段的学生也很有帮助和启发性。
英文摘要
We apply a thin metal rod (copper rod) as a probe in the alternating magnetic field generated by a Helmholtz coil, and measure the variation of the induced electromotive force (EMF) on the metal rod at different radial positions of Helmholtz coil. Experimental results show that the induced EMF is zero when the center of the metal rod passes through the center of the cylindrical magnetic field inside the Helmholtz coil. When the metal rod is displaced from the center of field to different radial positions, the induced EMF gradually increases from zero, reaches a maximum at a certain position, and then decreases monotonically as the radial distance continues to increase. At the position where the induced EMF reaches its maximum, the metal rod intersects the radial cross-section of the internal magnetic field of the Helmholtz coil at two points, with a small central portion of the rod located inside the Helmholtz coil and the two end portions outside the coil. To explain the experimental phenomena, we construct four simplified models of the magnetic field distribution based on the actual field distribution of the Helmholtz coil to quantitatively investigate the radial variation of the induced EMF along the metal rod. Our theoretical results show that the four models yield similar results and can all qualitatively explain the experimental data curves, particularly reproducing well the variation trend of the induced EMF and the position of the extremum point. The result of piecewise function fitting model is quantitatively in good agreement with the experimental data. This work is also very much helpful and instructive for undergraduate-level students.
Comments29 pages, 10 figures, 2 tables
