Electric Fields and Potential

PIRA Classification 5B

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.

5B10. Electric Fields

PIRA #

Demonstration Name

Abstract

5B10.10

hair on end

While standing on an insulated stool, charge yourself up with a Van de Graaff generator.

5B10.11

hair on end

Charge Van de Graaff generator with a Wig on the dome and without grounding ball.

5B10.13

pithball plate and flying balls

Place a plate with pith ball hanging on strings on an electrostatic generator. Also place a cup filled with styrofoam balls on an electrostatic generator.

5B10.15

Van de Graaff streamers

Attach ribbon streamers to the top of a Van de Graaff generator.

5B10.15

Van de Graaff streamers

A small stand with thin paper strips is placed on an electrostatic generator.

5B10.15

Van de Graaff with streamers

Show Van de Graaff with paper streamers, then hair on end.

5B10.16

recoiling tentacles

Place the electrostatic plume made out of nylon rope near the other terminal of the Wimshurst machine.

5B10.21

electric rosin

Melt rosin in a metal ladle and attach to a static machine. When the machine is cranked and the rosin slowly poured out, jets of rosin follow the electric field.

5B10.22

electrostatic painting

Clip the can to ground and a metal object to be painted to the Van de Graaff generator. Point out that the paint goes around to the back too, and it is thickest on the edges.

5B10.23

MgO smoke

Fill an unevacuated bell jar with MgO smoke and they will form three dimensional chain-like agglomerates between electrodes.

5B10.23

orbiting foil

Throw a triangle of aluminum foil into the field of a Van der Graaff and it comes to equilibrium mid-air. Give it a half-twist, and it will orbit in a horizontal circle below the sphere.

5B10.24

charge motion in an electric field

A charged ball on a dry ice puck is launched toward a Van de Graaff generator. The motion is recorded with strobe photography.

5B10.25

confetti (puffed wheat)

Confetti (puffed wheat, styrofoam peanuts) flies off the ball of an electrostatic generator.

5B10.25

confetti on electrostatic generator

Confetti flies off the ball of an electrostatic generator.

5B10.25

streamers

Fray the end of a nylon clothesline and charge with an electrostatic machine to show repulsion.

5B10.26

eletrified strings

A bunch of hanging nylon strings are charged by stroking with cellophane causing repulsion.

5B10.26

electrified strings

Charge a mop of insulating strings.

5B10.26

shooting down charge

Use the piezoelectric pistol to discharge the electrified strings.

5B10.30

electric chimes

A ball bounces between charged metal chimes.

5B10.30

electric chimes

Insert a metalized ping-pong ball between two highly charged metal plates.

5B10.30

electric chimes

A small metal ball hangs on a thread between two bells attached to an electrostatic machine.

5B10.30

electrostatic ping-pong balls

Conductive ping pong balls bounce between horizontal plates charged with a Wimshurst.

5B10.31

jumping particles

Aluminum powder bounces between two horizontal plates 1 cm apart attached to a static machine. Metalized pith balls bounce between an electrode at the top of a bell jar and the plate.

5B10.32

Van de Graaff chime

Toss a small foil near the charged sphere (see AJP 32(1),xiv - 5B10.33) and then bring a grounded ball close to show the chime effect.

5B10.33

electrostatic ping-pong

A fluffy cotton ball travels back and forth between an electrostatic generator and a lighted cigar.

5B10.35

electrostatic ping pong

Bounce a conducting ball hanging between two plates charged with a Wimshurst.

5B10.40

fuzzy fur field tank

"Fur" in mineral oil aligns along field lines from charged electrodes.

5B10.40

"velveteens"

Fine black fiber clippings in castor oil are used to show electric field between electrodes.

5B10.40

electric fields between electrodes

Charged electrodes are placed in a tank of mineral oil containing velveteen and the pattern is projected on the overhead.

5B10.40

fuzzy fur field tank

Bits of material suspended in oil align with an applied electric field. Several pole arrangements are shown.

5B10.40

electric field

A pan on the overhead projector contains particles in a liquid that align with the electric field.

5B10.41

repelled air bubbles

A stream of air bubbles in an oil bath are repelled in the region of an inhomogeneous field.

5B10.42

epsom salt on plate

Sprinkle Epson salt on a glass plate with two aluminum electrodes. Tap to align the crystals.

5B10.43

ice filament growth

An ice filament pattern shows the electrical field configuration. Place a PZT transducer on a block of dry ice.

5B10.50

mapping force with "electric doublet

Two pith balls charged oppositely and hanging from a rod are used to map out the field in the region of charged conductors.

5B10.51

plotting equipotential lines

A method for plotting equipotential lines from electrodes in a pan on water.

5B10.52

finger on the electrophorus

Charge and electrophorus., then trace a circle on it with your finger and probe the resulting field with a pith ball on a long thread.

5B10.53

extent of electric field

Hold an electroscope several feet away from a static machine and observe the electroscope leaves rise and fall as sparking occurs.

5B10.54

mapping field potential, voltage

A wire held in the flame of a candle and attached to a grounded electroscope is held near a Van de Graaff generator. Mount two candles on a insulator and attach the second to the case of the electroscope to measure voltage.

5B10.54

mapping potential field

A small alcohol lamp attached to an electrostatic voltmeter can be used to map potential fields.

5B10.55

liquid crystal mapping

An electrode configuration is painted onto a conducting paper with temperature sensitive encapsulated liquid crystals. Joule heating causes color changes.

5B10.55

liquid crystal mapping

An alternate method (to AJP 41(12),1314) of preparing liquid crystal displays of electric fields.

5B10.57

double brass plate measurement

The field around a large sphere is measured by separating two brass plates and measuring the charges with a ballistic galvanometer.

5B10.58

electric field indicator

A point on the end of a 500 Mohm resistor connects to a neon bulb in parallel with a small capacitor.

5B10.60

electric fields of currents

Current carrying conductors are made of transparent conducting ink on glass plates. Sprinkle on grass seeds to demonstrate the electric lines of force inside and outside the conducting elements.

5B10.61

electric fields of currents

Draw a circuit on glass or mylar with a soft lead scoring pencil. Dust the glass with small fibers while the current is flowing.

5B10.62

water drop model of charged particle

A water drop model demonstrates the motion of a stream of charged particles in an electric field.

5B10.70

other surfaces

see 8C20.20,1L20.10

5B10.70

rubber sheet model for fields

Roll balls over a 6'x4' frame with a stretched rubber surface, distorting it with dowels to represent charges.

5B10.70

model of field potential

A sheet of rubber is pushed up and down with dowels to represent positive and negative charges.

5B10.71

stretched membrane field model

A rubber sheet stretched over a large quilting hoop models electric fields.

5B20. Gauss' Law

PIRA #

Demonstration Name

Abstract

DCS #

DEMONSTRATION

ABSTRACT

5B20.10

Faraday's ice pail

While standing on an insulated stool, charge yourself up with a Van de Graaff generator.

5B10.11

Faraday's ice pail

Charge Van de Graaff generator with a Wig on the dome and without grounding ball.

5B20.10

Faraday ice pail

Charge a bucket with a Wimshurst and transfer charge from the inside and outside of the bucket to an electroscope.

5B20.11

big Faraday ice pail

A 55 gal. drum Faraday ice pail and other stuff.

5B20.12

Faraday ice pail

A Faraday ice pail made of two concentric wire mesh cylinders connected to a Braun electroscope.

5B20.15

Faraday's ice pail on electroscope

A charged metal pail sits on an electroscope. A proof plane transfers charge from the inside or outside to another electroscope.

5B20.15

butterfly net experiment

Turn a charged butterfly net inside out and the charge is still on the outside.

5B20.16

Faraday ice pail on electroscope

A charged copper beaker placed on an electroscope is touched on the outside or inside with a proof plane.

5B20.30

sheilded electroscope

A charged rod is brought close to a gold leaf electroscope in a wire mesh cage.

5B20.30

electroscope in a cage

Enclose an electroscope in a cage of heavy wire screening.

5B20.30

Faraday cage

Bring a charged rod near a Braun electroscope, then cover the electroscope with a wire mesh cage and repeat.

5B20.31

electroscope in a cage on Wimshurst

A screen cage shields an electroscope from a charged rod.

5B20.33

pith balls in a cage

Metal coated pith balls are suspended inside and outside of a metal screen cylinder attached to a electrostatic machine.

5B20.35

radio in a cage

Place a wire mesh cage over a radio.

5B20.35

radio in Faraday cage

Place a wire mesh cage over a radio.

5B20.36

VTVM in a cage

Mount the inputs to a VTVM in a Faraday cage. Show charge transfer from plastic strips.

5A20.28

beer can pith balls

Aluminum beer cans are used instead of pith balls to show repulsion of like charges.

5A20.30

Myar balloon electroscope

Balloon electroscopes, helium filled or normal, can be painted with aluminum and charged with a Van de Graaff.

5A20.30

balloons on Van de Graaff

Tape mylar balloons on conducting strings to a Van de Graaff generator.

5A20.30

Van de Graaff repulsion

Hang an aluminized balloon is hung from a rod attached to the Van de Graaff electrode to demonstrate repulsion of like charges.

5A20.32

electrostatic spheres on air table

5A20.35

Coulomb's law balance

The PSSC soda straw balance is adapted to make a simple Coulomb's law balance.

5A20.40

aluminum sheet electroscope

Two squares of aluminum foil are suspended from wires across a glass rod.

5A20.41

large leaf electroscope

A 15" length of 1 1/2" mylar tape is suspended along a brass strip.

5A20.50

measuring Coulomb's law

An optical lever and damper make this apparatus useful to demonstrate Coulomb's law. Diagram, Construction details in appendix, p. 1311.

5B30. Electrostatic Potential

PIRA #

Demonstration Name

Abstract

DCS #

DEMONSTRATION

ABSTRACT

5B30.10

surface charge density - balls

While standing on an insulated stool, charge yourself up with a Van de Graaff generator.

5B10.11

charged ovoid

Charge Van de Graaff generator with a Wig on the dome and without grounding ball.

5B30.20

surface charge density

Proof planes of the same area take charge from the flat or pointed end of a charged zeppelin shaped conductor.

5B30.20

charged Zeppelin

Use a proof plane and electroscope to compare charge densities at different points on a egg shaped conductor.

5B30.22

charge distribution on spheres

Read this one. Determine the charge distribution as spheres are brought close to a charged sphere.

5B30.24

surface charge density with cans

Transfer charge from the edge of a can on a source to the inside of a second can.

5B30.25

charge on spheres

Spheres of different diameters are brought to the same potential and inserted into a Faraday ice pail to show different charges.

5B30.26

spark gaps

Connect an electrostatic voltmeter to the terminals of an static machine and observe the voltage while varying the spark gap.

5B30.27

measure the second derivative of pot

A two point probe measures potential, and a five point probe measures the second derivative of potential. Diagram.

5B30.28

potential during discharge

An electroscope is connected to the ball of the electric chime to observe the decrease on potential as the ringing diminishes.

5B30.30

lightning rod

Insert a sphere and point of the same height between horizontal metal plates charged by a Wimshurst.

5B30.30

lightning rod

Insert a sphere and point of the same height between horizontal metal plates charged by a Wimshurst.

5B30.30

lightning rod

Sparks jumping from a plane to a sphere will stop when a point is inserted.

5B30.30

lightning rod

Sparks discharge from a large ball suspended over a model house with a small ball in the chimney until a point is raised above the small ball.

5B30.35

point and ball with Van de Graaf

Hold a ball close to a Van de Graaff generator and then bring a point close.

5B30.35

Van de Graaff and wand

With paper streamers as a field indicator, bring a ball and point close to the Van de Graaff.

5B30.40

electric wind

A point attached to a Wimshurst blows a candle flame.

5B30.40

electric wind

A candle between pointed and plane electrodes attached to a Wimshurst will blow the flame.

5B30.40

electric wind

A candle flame held near a point connected to the positive side of an electrostatic generator will repel the flame as if there is a breeze of ions.

5B30.40

point and candle

Attach a sharp point to one terminal of a Toepler-Holtz generator and point it at a candle flame.

5B30.41

history of the electric wind

Covers discovery and early investigations, the dust controversy, and recent studies and applications.

5B30.42

corona discharge in air

The corona discharge from a point towards a candle flame and a pinwheel spinning.

5B30.43

cooling with electric wind

The electric wind from needle points cools a glowing nichrome wire heater.

5B30.44

corona current

A 1/2 Meg resistor in series with a galvanometer measure the current in a corona discharge from an electrostatic machine.

5B30.45

corona discharge

A charged aluminum rod with a needle at one end will charge a nearby sphere with like charge if the needle is pointed to the sphere and with opposite charge if the needle is pointed away.

5B30.45

escape of charge from a point

When charge is induced on an electrode with a point, the induced charge will escape and the charge on the induced electrode will be the same as on the inducing electrode.

5B30.45

charge by pointing

Charge a conductor by proximity to a point attached to a static machine.

5B30.46

discharging from a point

Three balloons filled with illuminating gas are suspended from a point and charged. The blunt end of a brass rod has little effect but the pointed end discharges the balloons when pointed at them.

5B30.46

darning needle discharge

The blunt end of a darning needle is placed on the charged conductor of an electroscope and the electroscope is discharged.

5B30.47

collapse the field

The point of a grounded needle is brought near a charged tinsel tassel and the tassel collapses.

5B30.48

electrical discharge from water drop

A drop of water placed on the positive electrode of a Wimshurst will form a corona but spit droplets when placed on the negative electrode.

5B30.49

point cathode effect

A point 1s biased to 1200 V in a Wilson cloud chamber.

5B30.50

pinwheel

A pinwheel spins when attached to a Wimshurst generator.

5B30.50

electrostatic pinwheel

A conducting pinwheel spins when connected to a Wimshurst.

5B30.50

pinwheel

A pinwheel rotates when connected to either terminal of a static machine.

5B30.50

pin wheel

Place a pinwheel on a Van de Graaff generator.

5B30.51

electrostatic solar system

A double pinwheel rotates when connected to a Wimshurst.

5B30.60

electrostatic precipitator

Clear smoke in a chimney with points are connected to a Wimshurst.

5B30.60

Cottrell precipitator

Clear a smoke filled tube by a discharge from wire points.

5B30.60

smoke precipitation

Demonstrate smoke particles precipitating in a strong electric field in an artificial chimney.

5B30.60

smoke precipitation

Attach a Wimshurst to terminals at each end of a glass tube filled with smoke.

5B30.90

energy in the discharge

Light some alcohol or a Bunsen burner with the spark from a static machine.

5B30.91

gas explosion by spark

A spark plug hooked to a static machine is used to explode a mixture of hydrogen and oxygen in a closed container.

5B30.95

human chain

All students hold hands with one student holding one knob of a static machine and the other holding a metal rod near the other knob.

5B30.96

discharge through body

A student standing on the floor touches other students standing on insulated stands holding on to the two knobs of a static machine.

Demonstrations

Home

fw: ElectricFieldsAndPotential (last edited 2013-07-12 18:17:35 by localhost)