著者

矢ヶ崎 克馬 幾島 康夫 照屋 全次 当山 忠久 Yagasaki Katsuma Ikushima Yasuo Teruya Zenji Toyama Tadahisa

出版者

琉球大学理学部

雑誌

琉球大学理学部紀要 = Bulletin of the College of Science. University of the Ryukyus (ISSN:02869640)

巻号頁・発行日

no.36, pp.15-23, 1983-09

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The Planck's constant has been measured in the practical training of the special course of physics with an equipment using white light with color filters, but, according to the instruction, the results obtained were very poor. In this investigation, the critical photo-current coinside with the critical wave length of the color filter is determined reasonably by knowing the wave length dependences of the intensity of radiation of the white light source and the sensitivity of electron emission of the phototube and the decreasing of the reaching ratio of photo-electrons with higher energy than that of the inverse field from the photo - electric surface to the anode. The logarithmic method is the most suitable for determination of the critical photo-current. The values obtained with this method are within 3% of error compared with the accurate value. At the same time, the differential method and that using the line spectrum source are performed with a fair accuracy.