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ERIC Number: EJ891997
Record Type: Journal
Publication Date: 2007-Apr
Pages: 2
Abstractor: As Provided
Reference Count: 6
ISSN: ISSN-0031-921X
Make a Mystery Circuit with a Bar Light Fixture
Lietz, Martha
Physics Teacher, v45 n4 p244-245 Apr 2007
Teachers have been building mystery circuits or so-called "black box circuits" to use as a demonstration with their students for years. This paper presents an easy way to make simple mystery circuits using inexpensive light fixtures (see Fig. 1) available at almost any home improvement store. In a black box circuit, only the lightbulbs are visible and the wiring in these circuits is hidden from the students. The students are then presented with the challenge of deducing the nature of the electrical connections hidden by the black box. The students may remove one or more lightbulbs from the circuit to watch how the brightness of the other bulbs changes and, from this, deduce which bulbs are connected in series and which are connected in parallel.
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: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A