Abstract: This paper presents an experimental study and analysis of three key issues that often confusestudents in the teaching of the photoelectric effect experiment. First, by comparing the stopping voltagesmeasured using the intersection method and the compensation method under different aperture diameters, theeffects of dark current and background current on the measurement of Planck's constant are quantitativelyevaluated, and the effectiveness of the compensation method is verified. Second, a comparison between a high-pressure mercury lamp and an LED light source reveals that the mercury lamp, with its sharp line spectrum,better conforms to the " monochromatic light" assumption, whereas the spectral broadening of the LEDintroduces deviations in the determination of the stopping voltage, thereby increasing the caleulation error ofPlanck's constant. Finally, the observed "inversion" phenomenon in the current-voltage curves at diferentwavelengths is analyzed.It is shown that the magnitude of the saturated photocurrent depends not only on thelight intensity but also on the relative spectral intensity of the light source at that wavelength and theransmiance of the optical filter. The experimental results are consistent with theoretical expectations. Thisstudy provides a reference for improving the teaching of the photoelectric effect experiment and helps studentsgain a deeper understanding of the sources of experimental errors and the underlying physical picture.
孙 云 , 李 勇, 孙文斌, 周亚琦 , 刘传晋 , 王 锟 . 光电效应实验教学中三个关键问题的探讨[J]. 大学物理实验, 2026, 39(4): 27-33.
SUN Yun, LI Yong, SUN Wenbin, ZHOU Yaqi, LIU Chuanjin, WANG Kun. Exploration of Three Key Issues in the Teachingof the Photoelectric Effect Experiment. Physical Experiment of College, 2026, 39(4): 27-33.
