Maybe somewhere in your home there's a long hallway or a stairway with a light that you can turn on from either end. It's a nice convenience, but did you ever wonder how it's wired up to work that way? The goal of this project is to build a similar circuit with switches, flashlight batteries and a flashlight bulb (obviously, household circuits are not safe to experiment with). You'll need to understand the difference between connections made in series and connections made in parallel in an…
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An electric current produces a magnetic field. You can take advantage of this fact to make a simple apparatus to test the electrical conductivity of various materials, including both solids and liquids. The detector consists of a coil of wire, with a magnetic compass inside it. You connect one end of the coil to a D-cell battery. The other end of the coil is connected to whatever material you are testing, and the material, in turn, is connected to the other end of the D-cell. In other…
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You may know Lewis Carroll as the author of Alice in Wonderland, but did you know that in real life he was a mathematician who studied symbolic logic and logical reasoning? How can math help you solve Lewis Carroll's Logic Game? (Bogomolny, 2006) How are algorithms for solving the game Sudoku similar to solving a logic problem? (Hayes, 2006) For the super-advanced mathematical genius, try to evaluate currently available, logic-based computational tools, or design a better one!…
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There are two main types of materials when it comes to electricity, conductors, and insulators. What are they made of? Find out by testing different materials in a circuit to see which ones conduct the most electricity.
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Elec_p018

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- Less Details

Time Required

Very Short (≤ 1 day)

Prerequisites

None

Material Availability

Readily available

Cost

Very Low (under $20)

Safety

When working with electricity, take precautions and beware of electric shock.

In the United States, lighting for homes accounts for about 14% of all residential electricity usage (EIA, 2014). That's billions of dollars worth of electricity per year. The U.S. has passed legislation to phase out older, more inefficient incandescent light bulbs, and they are being replaced with newer, more-efficient bulb types like compact fluorescent lights (CFLs) or light-emitting diodes (LEDs). How much energy (measured in kilowatt-hours [kWh]) and how much money could be saved by…
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Solar cells are an alternative method for generating electricity directly from sunlight. With this project, you can get down to the atomic level and learn about the world of solid-state electronics as you investigate how solar cells work. Your experiment will measure the effect of changing light intensity on power output from the solar cell. A possible variation would be to investigate the effect of changing the color of the light.
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Energy_p014

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- Less Details

Time Required

Short (2-5 days)

Prerequisites

None

Material Availability

Specialty electronics components required, see Materials list for details

LEDs (light-emitting diodes) are electronic components that convert a portion of the electrical energy flowing through them into light. How does the intensity of the light produced vary with the current flowing through the LED? To find out, you'll build some simple circuits to vary the current flowing an LED. You'll also build a simple light-to-voltage converter circuit to measure LED output.
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You can take advantage of electrochemistry and make a battery to clean tarnished silverware without scrubbing. You should learn about how batteries work and study oxidation-reduction reactions so that you can explain how this process works. You'll need a pan large enough to hold the pieces of silverware, and deep enough to cover them in solution while boiling gently. Line the pan with aluminum foil, and place the silverware inside the pan, making sure that each piece touches the foil. Add…
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A magic square is an arrangement of numbers from 1 to n2 in an n x n matrix. In a magic square each number occurs exactly once such that the sum of the entries of any row, column, or main diagonal is the same. You can make several magic squares and investigate the different properties of the square. Can you make an algorithm for constructing a Magic Square? Can you show that the sum of the entries of any row, column, or main diagonal must be n(n2+1)/2? Are there any other hidden properties of a…
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Want to know how electrical engineers "trap" the energy in a circuit to make your favorite electrical appliance? Video games, computers, phones, and many other electrical devices use "resistors" in different ways to control the electricity in a circuit. In this experiment, you can make your own resistors out of pencils, and test the effect a resistor has on a circuit.
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