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ERIC Number: EJ860281
Record Type: Journal
Publication Date: 2008-Oct
Pages: 3
Abstractor: As Provided
Reference Count: 5
ISSN: ISSN-0031-921X
Computer-Based Experiment for Determining Planck's Constant Using LEDs
Zhou, Feng; Cloninger, Todd
Physics Teacher, v46 n7 p413-415 Oct 2008
Visible light emitting diodes (LEDs) have been widely used as power indicators. However, after the power is switched off, it takes a while for the LED to go off. Many students were fascinated by this simple demonstration. In this paper, by making use of computer-based data acquisition and modeling, we show the voltage across the LED undergoing an exponential decay after the power is switched off. We also describe a new approach for determining Planck's constant using LEDs. The simple experiment can be used either in an interactive lecture demonstration or an entry-level physics lab.
American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education; Postsecondary Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A