Recently, small computer fans have been demonstrated to be an effective method for teaching simple resistive circuits both qualitatively and quantitatively. The current through the fans is related to the rotational speed of the fans and allows multiple senses to be engaged (touch, sight, and hearing). Methods for learning simple circuits in an…

Transistors are semiconductor devices that form the basis of today's electronic technology. Following the first step of developing a point-contact transistor developed by Walter Brattain and John Bardeen in 1947, the development of the junction transistor by William Shockley in early 1948 opened the way for rapid progress in electronic technology.…

Many physics textbooks describe the way in which a capacitor in an RC circuit charges and discharges over time. A circuit that consists of a capacitor that is connected to a voltage divider as shown in Fig. 1 is commonly addressed, but the textbooks limit the discussion to the time immediately after the switch is closed and a long time after the…

In a classical electronic laboratory, there is an experiment where a diode is connected in a series with a resistor and a variable DC voltage source in order to draw the characteristic I-V curve of the diode. Input voltage is gradually increased starting from 0 V, and the potential difference between the diode's terminals is read by using a…

In this work we describe a simple setup for measuring electrostatic charge and polarity in electrostatic experiments. This low-cost detector only requires a graphite pencil, a capacitor, two switches, and a voltmeter, and holds the promise of transforming qualitative activities that are commonly used to teach electrostatics into quantitative…

Measuring magnetic induction is occasionally performed by our students during their academic training in physics. Among the various methods used to measure it, the Hall effect is the most common and widespread. Another way consists of employing an electronic flux-meter. It is constituted by a small flat coil (SFC) connected to the input of an…

The incandescent bulb has been a useful tool for teaching basic electrical circuits, as brightness is related to the current or power flowing through a bulb. This has led to the development of qualitative pedagogical treatments for examining resistive combinations in simple circuits using bulbs and batteries, which were first introduced by James…

Acharge pickup detector was developed at the University of Colorado for use in classroom demonstrations and in the dust accelerator at the Institute for Modeling Plasma, Atmospheres and Cosmic Dust (IMPACT). The detector can be used in a physics classroom to help high school and introductory-level physics students connect electromagnetic phenomena…

Providing instant visual feedback, thermal imaging cameras are becoming more and more popular tools not only in industrial applications, but also in physics education. Continuously decreasing prices, modules compatible with smart portable devices, and intuitive operation make thermal measurements available for schools and attractive for students.…

A bridge rectifier is a diamond-shaped configuration of diodes that serves to convert alternating current(AC) into direct current (DC). In our world of AC outlets and DC electronics, they are ubiquitous. Of course, most bridge rectifiers are built with regular diodes, not the light-emitting variety, because LEDs have a number of disadvantages. For…

In April 1820, Hans Christian Ørsted noticed that the needle of a nearby compass deflected briefly from magnetic north each time the electric current of the battery he was using for an unrelated experiment was turned on or off. Upon further investigation, he showed that an electric current flowing through a wire produces a magnetic field. In 1831…

Calculating the effective resistance of an electrical network is a common problem in introductory physics courses. Such calculations are typically restricted to two-dimensional networks, though even such networks can become increasingly complex, leading to several studies on their properties. Furthermore, several authors have used advanced…

The "LCR" circuit is an important topic in the course of electricity and magnetism. Papers in this field consider mainly the forced oscillations and resonance. Our aim is to show how to demonstrate the free and self-excited oscillations in an "LCR" circuit. (Contains 4 figures.)

Describes the nature, history, and applications of Doppler radar detecting the speed of moving object. Gives an example of measuring the radial velocity of a scattered wave. (YP)