Resistance
PIRA classification 5D
Grayed Demos are either not available or haven't been built yet |
Please note that these tables have not yet been edited to match the equipment that is available within the UW-Madison lecture demo lab. There maybe many items listed within these tables that we either "can not do" or have available.
Resistance Characteristics
PIRA # |
Demonstration Name |
Subsets |
Abstract |
5D10.10 |
resistor assortment |
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5D10.11 |
scaled up resistor box |
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Rebuild an old resistance box with larger numbers. |
5D10.20 |
characteristic resistances |
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Connect one meter lengths of various wires in series and measure the voltage across each. |
5D10.20 |
characteristic resistance |
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Measure voltages on a commercial board with seven one meter lengths of various wires is series so all carry the same current. |
5D10.20 |
resistance wires |
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Place 6V across a set of wires of different lengths and/or diameters and measure the currents. |
5D10.22 |
resistance characteristic of arc |
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Measure the current and potential across a small arc as the series resistance is varied. |
5D10.40 |
resistance model |
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Balls are rolled down an incline with pegs. |
5D10.40 |
model of resistance |
pira200 |
A ball is rolled down a board with randomly spaced nails. |
5D10.40 |
charge motion demonstrator |
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Small balls are rolled down a board with nails scattered in an almost random pattern. Diagram. |
5D10.40 |
electron motion model |
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Ball bearings are simultaneously rolled down two ramps, one with pegs and one without. |
5D10.50 |
current model with Wimshurst |
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Resistivity and Temperature
PIRA # |
Demonstration Name |
Subsets |
Abstract |
5D20.10 |
wire coil in liquid nitrogen |
pira200 |
A lamp glows brighter when a series resistance coil is immersed in liquid nitrogen. |
5D20.10 |
resistance at low temperature |
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A lamp glows brighter when a series resistance coil is immersed in liquid air. |
5D20.10 |
cooled wire |
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A copper coil in series with a battery and lamp is immersed in liquid nitrogen. |
5D20.11 |
resistance at low temperature |
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A "C" battery, 3 V flashlight bulb, and a copper wire coil make a hand held temp coefficient of resistivity apparatus. |
5D20.12 |
audible temp-dependent resistance |
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The resistor plunged into liquid nitrogen is part of a voltage controlled oscillator that drives a speaker. |
5D20.12 |
cooling |
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Current is increased in a long U of iron wire until it glows, then half is inserted into a beaker of water. |
5D20.14 |
superconducting wire |
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Cool a coil of NbTi wire in a series circuit with a 12 volt car battery and lamp first in liquid nitrogen, then helium. The voltage across the coil is monitored and the lamp brightness is observed. |
5D20.15 |
flame and liquid nitrogen |
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Resistance coils are heated and cooled with a test light bulb in series. |
5D20.15 |
temperature dependence of resistance |
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Two sets of bulbs in series with coils, one put in liquid nitrogen and the other in a flame. |
5D20.16 |
temperature coefficent of resistance |
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Two coils of different material but the same resistance are placed in a Wheatstone bridge and either is heated or cooled. |
5D20.20 |
iron wire in flame |
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Heat a coil of iron wire in series with a battery and a lamp and the lamp will dim. |
5D20.20 |
iron wire in a flame |
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A coil of forty turns of iron wire is heated in a flame while connected in series with a light bulb circuit. |
5D20.20 |
putting the light out by heat |
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A coil of iron wire wound on a porcelain core in series with a lamp and battery is heated until the lamp goes out. |
5D20.20 |
heated wire |
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Heat a coil of iron wire in series with a battery and a lamp. |
5D20.21 |
flame |
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A coil of nickel wire connected to a battery and galvanometer is heated in a flame. |
5D20.30 |
pos and neg resistance coefficients |
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Measure current and resistance at various voltages for a carbon and tungsten bulb. |
5D20.30 |
carbon and tungsten lamps |
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Plot current vs. voltage for carbon and tungsten lamps. |
5D20.31 |
resistance of light bulbs |
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The V/I curves for tungsten and carbon filament lamps are shown on a dual trace storage oscilloscope. |
5D20.32 |
temperature of incandescent lamps |
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Two silicon solar cells with interference filters measure the light at different wavelengths for use in determining the temperature of the filament. |
5D20.40 |
resistance thermometer |
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Attach No. 14 copper leads to a platinum coil and use with a Wheatstone bridge. |
5D20.50 |
thermistors |
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Use a good kit of commercial thermistors and display the differential negative resistance of a fast thermistor on a transistor curve tracer. |
5D20.50 |
thermistor |
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Show the resistance of a thermistor placed in an ice water bath. |
5D20.60 |
conduction in glass at high temp |
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A simple version of glass conduction using binder clips and window glass. |
5D20.60 |
conduction in glass at high temp |
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Heat a capillary tube in a Bunsen burner until it is hot enough to sustain a current that maintains a bright glow. |
5D20.60 |
conduction in glass |
pira200 |
Two light bulbs are connected in series to a power supply. One of the ligh bulbs is smashed with a mallet and the filaments is cut off. Then, the glass stem is heated with a blow torch. |
5D20.61 |
negative temp coeff of resistance |
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A Nerst glower must be heated with a flame until the resistance is low enough to sustain electrical heating. |
Conduction in Solution
PIRA # |
Demonstration Name |
Subsets |
Abstract |
5D30.10 |
conductivity of solutions |
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Dip two metal electrodes in series with a light bulb in various solutions. |
5D30.10 |
conduction thru electrolytes |
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Immerse two copper plates in series with a lamp in distilled water, add barium hydroxide, then sulfuric acid. |
5D30.10 |
conduction thru electrolytes |
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Put two copper plates in series with a lamp in distilled water and salt or acid is added. |
5D30.10 |
conductivity of solutions |
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Two electrodes in series with a 110 V lamp are dipped into distilled water, salt water, a sugar solution, a vinegar solution, and tap water. |
5D30.13 |
salt water string |
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5D30.15 |
electrolytic conduction on chamios |
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Suspend a chamois between ringstands, show no conduction with a battery, resistor, meter. Soak in distilled water, repeat, then sprinkle on salt |
5D30.20 |
speed of ions |
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Show KMnO4 migrating with current towards the positive electrode in KNO3. |
5D30.20 |
migration of ions |
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Permanganate ions migrate in an electric field. |
5D30.21 |
ionic speed |
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Dip two platinum electrodes into an ammoniated copper sulfate solution containing some phenophthalein. |
5D30.22 |
ionic speed |
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Blue moves from the anode of in a potassium chloride gel when 120 volts is applied. |
5D30.23 |
ionic speed |
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Measuring the speed of hydrogen and hydroxyl ions in a potassium chloride gel. |
5D30.30 |
pickle glow |
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Conduction in Gases
PIRA # |
Demonstration Name |
Subsets |
Abstract |
5D40.10 |
Jacob's ladder |
pira200 |
A arc rises between rabbit ear electrodes attached to a high voltage transformer. |
5D40.20 |
conduction of gaseous ions |
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A nearby flame will discharge an electroscope. |
5D40.21 |
discharge with flame |
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A flame connected to a high voltage source is inserted between charged parallel plates. |
5D40.25 |
blowing ions by a charged plate |
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Compressed air blows ions from a flame through the area between charged parallel plates onto a mesh hooked to an electrometer. |
5D40.25 |
discharge by ions in a tube |
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Electrodes at the bottom, middle, and top of a tube are connected to an electrometer while a Bunsen flame is burned at the bottom. |
5D40.27 |
recombination of ions |
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Ions from a flame are drawn past a series of charged plates attached to a Zeleny electroscope. |
5D40.28 |
separating ions from flame |
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Shadow project a flame between two charged metal plates to observe separation of gas into two streams of oppositely charged ions. |
5D40.30 |
ionization by radioactivity |
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Discharge an electroscope with a radioactive source. |
5D40.32 |
ionization in air |
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Various sources of ionization are brought near parallel wires attached to a 100 V battery and a Zeleny electroscope. |
5D40.33 |
saturation |
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The voltage across a plate close to a wire mesh is increased with a radioactive source nearby and the current is observed with a Zeleny electroscope. |
5D40.34 |
ion mobilities |
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A second mesh is inserted into the apparatus of A-2 and an alternating potential increased until the electroscope oscillates. |
5D40.35 |
conduction in air by ions |
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An electrometer measures the current between parallel plates as a flame is burned between them or an alpha source is held nearby. |
5D40.36 |
Cerberus smoke detector |
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Combustion products decrease conductivity in a chamber with an alpha source. |
5D40.40 |
conduction from hot wire |
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A constantan wire held near a charged electroscope causes discharge when it is heated red hot. |
5D40.41 |
thermionic effect in air |
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A Zeleny electroscope indicates electron emission from a wire when it is heated. |
5D40.42 |
thermionic emission |
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A commercial tube. Apply 90 V forward and reverse and monitor the current. |
5D40.50 |
neon bulb resistivity |
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A neon lamp lights at about 80 V and shuts off at about 60 V. |
5D40.80 |
ionization by X-rays |
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Discharge an electroscope with X-rays. |
5D40.80 |
x-ray ionization |
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Discharge an electroscope with x-rays. |
5D40.81 |
ionization by X-rays |
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An X-ray beam is passed through a simple ionization chamber. |
5D40.99 |
electrohydrodynamics |
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read this again - practical examples are ink jet printing and electrically driven convection. |