## DC Circuits

PIRA classification 5F

 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.

# 5F10. Ohm's Law

 PIRA # Demonstration Name Abstract 5F10.05 charge density in circuits Two demonstrations: first, an electroscope is used to probe the charge density along a large resistance attached to a 5 KV supply, and second, an example where current is flowing through a resistance with no change in potential. 5F10.10 Ohm's law Measure current and voltage in a simple circuit. Change the voltage or resistance. 5F10.10 Ohm's Law An ammeter, voltmeter, rheostat, and battery pack are connected to demonstrate Ohm's law. 5F10.10 Ohm's law A battery, rheostat, and meters in a circuit. 5F10.10 Ohm's law Measure current and voltage in a simple circuit. 5F10.10 Ohm's law Place 2, 4, and 6 V across a resistor and measure the current, then graph. 5F10.12 water analogy circuit A water analogy illustrates voltage drops across a dc circuit. 5F10.15 water Ohm's law analog 5F10.15 water analog A water analog of Ohm's law. 5F10.15 IR drop in a wire Clip wires from the terminals of flashlight lamps at various points along a stretched wire carrying 2 - 5 amps. 5F10.20 potential drop along a wire Lecture galvanometers configured as a voltmeter and ammeter measure current and voltage on several samples of wire of the same length. A slide clip can be used to vary length. 5F10.20 voltage drop along wire Measure the voltage at six points on a long resistance wire. 5F10.25 potential drop with Wimshurst A 3 m long wood bar is attached at one end to one terminal of a static machine. The other end can be grounded or insulated. Attach several electroscopes along the bar to show flow of charge and potential drop. 5F10.26 high voltage Ohm's law Two ends of a dry stick are attached to a static machine. Measure with an electrostatic voltmeter and microammeter.

# 5F15. Power and Energy

 PIRA # Demonstration Name Abstract 5F15.10 electrical equivalent of heat Measure the voltage and current to a heating coil in a calorimeter. 5F15.10 heat and electrical energy A heating coil in a calorimeter. 5F15.10 electrical equvalent of heat Voltage, current to a heater and temperature rise in water are measured. 5F15.10 electrocalorimeter Determine the power delivered by temperature change in water and compare to that computed from voltage, current, and time. 5F15.11 flow calorimeter Water is heated electrically as it flows through a tube. 5F15.12 heating by current from a static mot The ends of a piece of wood sealed in a glass tube are attached to a static machine. The half watt dissipated heats the air and an attached manometer measures the volume change. 5F15.15 KWH meter and loads Measure the power consumed by an assortment of household appliances. 5F15.16 heating with current Large currents are passed through No. 18 nichrome wire and the volts and amps are measured. 5F15.17 heating wires in series Several lengths of different wires of the same length are soldered together in series and a piece of paper is hung from each by soft wax. As current is passed through the wire, the paper falls off at different times. 5F15.20 hot dog cooker Hook nails to 110V and place them on and then in a hot dog. 5F15.20 hot dog frying Apply 110 V through a hot dog and cook it. 5F15.30 fuse with 30v lamp 5F15.31 fuse-wire problem With fuse wires of different diameters connected in parallel, which will burn out first? 5F15.32 vaporize wire with 500 amp surge Short a low voltage high current transformer with zinc coated iron wire. 5F15.33 fuse wire Fuse wire is used with a miniature house circuit. 5F15.34 fuses Fuse wire of different sizes are connected across a heavy copper buss. 5F15.35 fuse with increasing load 5F15.40 voltage drops in house wires Two resistance wires substituting for house wiring glow when they power a load of lamps and heaters. 5F15.45 I2R losses Copper and nichrome wires in series show different amounts of heating due to current. A paper rider on the nichrome wire burns.

# 5F20. Circuit Analysis

 PIRA # Demonstration Name Abstract 5F20.10 Kirchoff's voltage law Measure the voltages around a three resistor and battery circuit. 5F20.10 Kirchoff's voltage law Measure the voltages around a three resistor and battery circuit. 5F20.10 sum of IR drops Measure the voltages across three resistors and a battery in a series circuit. 5F20.13 voltage divider A simple series circuit of a battery and two resistors. 5F20.15 continuity of current Same as Eo-4. 5F20.15 continuity of current An ammeter can be inserted into any branch of a circuit to show currents in and out of a node. 5F20.16 conservation of current Measure the currents entering and leaving a node. 5F20.20 superposition of current Same as Eo-7. 5F20.20 superposition of currents Measure the current from one battery, a second in another position, and the combination in a circuit. 5F20.20 superposition Shows a standard superposition circuit. 5F20.25 reciprocity Shows a standard reciprocity circuit. 5F20.30 potentiometer A slide wire potentiometer is used with a battery and demonstration galvanometer. 5F20.30 potentiometer A slide wire potentiometer with a standard cell. 5F20.31 rheostat as potential divider Contrast the slide wire rheostat when used as a rheostat or potential divider. 5F20.32 long potentiometer Use a ten foot length of nichrome wire as a slide wire potentiometer. 5F20.33 rheostat potential divider A rheostat and six volt battery demonstrate a potential divider. 5F20.40 wheatstone bridge - slide wire The slide wire Wheatstone bridge. 5F20.40 wheatstone bridge - slide wire Two nichrome wires are stretched across the lecture bench and sliding clips connected to a galvanometer are used to find equal potential points. 5F20.41 wheatstone bridge - human galvan. Stretch a loop of close line previously soaked in salt solution in a parallelogram and hook the ends to a 110 V line. Touch two points of the same potential without shock. 5F20.42 wheatstone bridge A demonstration Wheatstone bridge with a built in meter and several plug in resistors. 5F20.45 lightbulb wheatstone bridge A Wheatstone bridge configuration with lightbulbs for resistors. 5F20.45 light bulb wheatstone bridge Four light bulbs in a Wheatstone bridge arrangement with light bulb indicator. 5F20.45 light bulb wheatstone bridge A light bulb Wheatstone bridge using 110 ac. 5F20.45 wheatstone bridge Four 60 W lamps in a diamond bridge with a 10 W lamp as the indicator. An additional 6 V lamp can be switched in when the circuit is balanced. 5F20.45 wheatstone bridge Three 110 V lamps and a rheostat make up the diamond of a Wheatstone bridge and a small lamp serves as an indicator. 5F20.50 series and parallel light bulbs A light bulb board with switches allows configuration of several combinations of series and parallel lamps. 5F20.50 series and parallel light bulbs A light bulb board with switches allows configuration of several combinations. 5F20.50 parallel and series light bulbs Three similar wattage lamps in series, three in parallel. 5F20.50 series-parallel circuits A series-parallel circuit with three bulbs and six switches can be connected 14 ways. 5F20.50 series/parallel light bulbs Three 110 V lamps are wired in series and three are wired in parallel. 5F20.51 light bulb board - 12 V A board with 12V bulbs and a car battery allow combinations of up to three series or three parallel loads. 5F20.55 series/parallel resistors Measure the current flowing through a wire resistor with 6 V applied and then series and parallel combinations. 5F20.56 wire combinations A wire circuit is arranged so a segment of n length can have 1 or n wires in parallel. Drawing. 5F20.60 equivalent series resistance A series of resistors in a circuit are replaced by a single resistor. 5F20.61 parallel resistance - integral value A formula for obtaining integral values of resistors in parallel to obtain an integral equivalent resistance. 5F20.61 equivalent parallel resistance Parallel resistors are replaced by a single resistor in a circuit. 5F20.63 Thevenin's equivalent resistance A Wheatstone bridge resistance circuit is used to reduce resistor combinations to an equivalent resistance. 5F20.64 equivalent circuit flasher A neon flasher circuit shows the combination rules for series and parallel combinations of resistance and capacitance by timing light flashes. 5F20.71 large circuit boards A modular circuit board made for 500 student auditoriums. 5F20.72 general circuits board A circuit board laid out so meters can be plugged in and readings taken for demonstrations of series-parallel circuits and Kirchhoff's laws. 5F20.75 three-way switch A large circuit board demonstrates a three way switch. 5F20.79 one boar, river, six people An electrical circuit for solving the problem of getting across the river. 5F20.95 equivalent resistance analog comput. Using the equivalent resistance of a circuit as an analog computer for finding the focal length of an optical problem.

= 5F30. RC Circuits =

 PIRA # Demonstration Name Abstract 5F30.10 capacitor and light bulb A large lelectrolytic capacitor, a light bulb, and a 120 V dc supply in series show a long time constant. 5F30.10 capacitor and light bulb A 5600 microF capacitor is charged and discharged through 7.5 and 40 W light bulbs. 5F30.10 long RC time constant A 5600 microF capacitor, a light bulb, and a 120 V dc supply in series show a long time constant where the bulb dims as the capacitor charges. 5F30.11 light the bulb Charge a capacitor with DC and discharge through a light bulb, try the same thing with AC. 5F30.12 discharge a capacitor Discharge a capacitor through a resistor. Read the voltage with a meter. 5F30.15 RC time constant on galvanometer A series RC circuit with a galvanometer. Diagram. 5F30.16 RC voltage follower Use a voltage follower to isolate the circuit from the display. 5F30.20 RC time constant on scope A circuit with a slow time constant (.1 - 10 sec.) is charged and discharged and the current and voltage are displayed on a dual trace storage scope. 5F30.20 RC charging curve Show charging and discharging a RC circuit with a battery on an oscilloscope. 5F30.21 RC time constant Show the time constant from an RC circuit on an oscilloscope. 5F30.21 RC time constant A plug in circuit board for showing RC time constants on the oscilloscope. 5F30.22 time constant of an capacitive cir. The time constant of a RC circuit driven by the calibration signal is shown on an oscilloscope. 5F30.28 finding R from time constant A circuit to measure high resistances by using an RC charging time. 5F30.50 series and parallel capacitors Two 2 microF capacitors in series or parallel with a 40 W lamp. 5F30.60 neon relaxation oscillator 5F30.60 blinking neon bulb A neon bulb in parallel with a capacitor will light periodically as the capacitor charges and discharges. 5F30.60 RC relaxation oscillator An RC relaxation oscillator has a neon lamp across the capacitor provide a visible discharge. 5F30.60 RC flasher circuit A neon lamp in parallel with the capacitor in a series RC circuit. 5F30.60 flashing neon light A battery powered neon light oscillator. 5F30.60 neon relaxation oscillator A circuit for a neon relaxation oscillation oscillator. Reference: AJP 13(12),415. 5F30.60 relaxation oscillator An RC neon light relaxation oscillator. 5F30.61 relaxation siren oscillator A double RC relaxation oscillator with slow and fast periods gives a siren waveform. 5F30.68 backward and forward waves RC circuits are used to get a wave in neon bulbs that goes from the sink to the source. 5F30.71 capacitance operated relay References but no information on the circuit. Bring your hand close to a aluminum plate and the relay triggers. 5F30.80 fun circuit One box has switches that control two lights in another box but only one wire connects the two boxes.

# 5F40. Instruments

 PIRA # Demonstration Name Abstract 5F40.10 sensitivity and resistance of a galv A circuit for the determination of galvanometric constants. 5F40.10 sensitivity and resistance of galvan Use external resistors to measure the resistance and sensitivity of a galvanometer. 5F40.15 voltmeter and electroscope Connect series resistance to a galvanometer to make a voltmeter with low sensitivity and measure several dry batteries in series with both the voltmeter and an electroscope. 5F40.20 converting a galvanometer to a voltm Knowing the resistance and sensitivity of a galvanometer, add a series resistance and check with a voltage. 5F40.20 galvanometer as voltmeter and ammete A galvanometer is used with shunt and series resistors. 5F40.21 loading by a voltmeter Measure the voltage across a high resistance circuit with high and low impedance voltmeters. 5F40.25 converting a galvanometer to a ammet Knowing the resistance and sensitivity of a galvanometer, add a shunt resistance and measure a current. 5F40.30 hot wire ammeter A crude hot wire galvanometer. 5F40.30 hot wire ammeter Diagram of a hot wire ammeter. (E-171). 5F40.35 iron vane meter Repulsion from induced magnetism in two soft iron bars in a solenoid forms the basis of a heavy current ammeter. 5F40.50 multimeters A couple multimeters are pictured.