Provides a schematic to build a black box experiment that uses light bulbs of various intensities. The students are to determine the complex circuit by unscrewing the bulbs and noting what happens. (MVL)

The use and misuse of the superposition principle to analyze electrical circuits are discussed. (KR)

Provides a simple routine which allows first-year physics students to use programmable calculators to solve otherwise complex electrostatic problems. These problems involve finding electrostatic potential and electric field on the axis of a uniformly charged ring. Modest programing skills are required of students. (DH)

Describes a method of network analysis that allows avoidance of Kirchoff's Laws (providing the network is symmetrical) by reduction to simple series/parallel resistances. The method can be extended to symmetrical alternating current, capacitance or inductance if corresponding theorems are used. Symmetric cubic network serves as an example. (JM)

Describes an experiment undertaken to determine what relative electric charges would result if three or more pieces of transparent tape were placed on top of each other and then separated one at a time. Makes suggestions for using the project in high school and undergraduate classes. (WRM)

Derives the current in the wire joining two points when n points are joined two by two by wires of equal resistance, and two of them are connected to the electrodes of a battery of electromotive force E and resistance R. (YP)

Describes the theory behind tapered resistors and liquid crystals and their use in the Duracell battery test strip. Presents related electrical problems for students. (JRH)

Two different methods of measuring the temperature of an incandescent lamp at various voltage levels are described. By observing the color produced at a particular voltage levels, the lamp's color as a function of temperature can be determined. Needed equipment include a variac, a voltmeter, and an ammeter. (KR)

A quantitative application of magnetic braking performed with an air track is described. The experimental measurement of the position of the glider as a function of time is calculated. (KR)

Describes the use of the black-box technique to explore electrical circuit design and circuit elements. (JRH)

Gives several sample experiment problems for electricity and magnetism. To solve an experiment problem, students have to do one or more of the following: clarify a poorly defined problem, divide a problem into parts, access the appropriate concept needed to solve each problem part, decide whether approximations are appropriate, design an…

Describes the nature of cognitive research. Misconceptions research in mechanics and electricity are reviewed. Research results on expert/novice differences in knowledge organization and problem solving are reviewed. Implications for classroom teaching are discussed. Lists 34 references. (YP)

Presents a mathematical problem that, when examined and generalized, develops the relationships between power and efficiency in energy transfer. Offers four examples of simple electrical and mechanical systems to illustrate the principle that maximum power occurs at 50 percent efficiency. (MDH)