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Physics and Astronomy Demonstrations

Electricity & Magnetism

 


Electrostatics


 

Electrostatics Box

PIRA: 5A10.10

Description: Items included in this box are as follows: silk, glass rod, fur, plastic rod, pith balls, resistor, charging plates, packing peanuts in a Ziploc bag, and a ping pong ball on a string. We have two boxes described as above. Numerous electrostatic demonstrations can be performed by using this box in conjunction with the Van de Graaff generator.

 

Electrophorus

PIRA: 5A10.20

Description: Use a metal plate on a handle to transfer charge from a large charged surface.

 

Suspended Balloons

PIRA: 5A10.31

Description: The balloon can be charged and then used to show attraction to neutral objects.

 

Scotch Tape & Electroscope

PIRA: 5A10.32

 

Zerostat

PIRA: 5A10.33

 

Suspended Rods

PIRA: 5A10.38

Description: Fur can be used to place a negative charge on a piece of PVC or glass pipe. If two pieces of PVC or glass are charged alike, the suspended pipe will be repelled by one held in the hand. The fur (+ charge) can be used to attract the suspended pipe. This exercise helps to demonstrate the existence of two types of charge as well as charge transfer.

 

Coulomb’s Law on the Computer

PIRA: 5A20.01

 

Flying Fur

PIRA: 5A20.11

 

Pith Balls

PIRA: 5A20.20

Description: Suspend two small pith balls from a common support and show either attraction or repulsion. Charge the two pith balls and they attract or repel.

 

Coulombs Law with Balloons

PIRA: 5A20.21

 

Ringing Bells

PIRA: 5A20.34

Description: Four bells are arranged so their strikers will transfer charge to ground. When the transfer occurs, the strikers hit the bells and thus the “ringing bells”.

 

Faraday Ice Pail

PIRA: 5A20.35

Description: An electric charge is placed on the inner metal mesh, and the outer mesh is connected to the electrometer and to an overhead voltmeter. The charge will run to the outer mesh when they are shorted.

 

Volta’s Hail Storm

PIRA: 5A20.36

Description: Styrofoam pieces will jump around in a jar when the Van de Graaff is connected to an electrode at the top of the hail storm apparatus. The Styrofoam is transferring charge from the electrode to ground.

 

Electric Potential with Electrometer

PIRA: 5A20.71

 

Electroscope Assortment

PIRA: 5A22.11

Description: The project-o-scope is an electroscope that is viewable on the overhead projector. The set of rods is used to show the two kinds of charge. The project-o-scope can be charged by both conduction and induction. The methods for testing for charge type with a charged electroscope can be shown. There is a toilet float electoscope as well.

 

Foam Model of Insulators & Conductors

PIRA: 5A30.05

Description: Three models are available for drawing analogies to insulators, semi-conductors, and conductors. The insulator has deep pockets which will hold steel balls (electrons) in place. The semi-conductor has shallow pockets and the conductor has no pockets, so the balls are free to roll around.

Insulators & conductor foam models 8.11

 

2 ” X 4 ” Attraction of Neutral Objects

PIRA: 5A40.30

Description: A 2” x 4” balanced on a watch glass can be easily moved with a charged rod.  The PVC pipe charged with the fur works quite well.

 

Water Deflection Chute

PIRA: 5A40.40

Description: Two metal plates through which a stream of water can flow. By using a charged rod, either the glass and silk or the PVC pipe and the fur, a stream of water is easily deflected.

 

Deflection of a Water Stream

PIRA: 5A40.41

 

Electrostatic Motor

PIRA: 5A50.05

Description: A motor operated by electrostatic charges drawn from an electrostatic generator.

 

Wimshurst Machine

PIRA: 5A50.10

Description: This machine will generate static electricity.

 

Van de Graaff Generator

PIRA: 5A50.30

Description: The Van de Graff can quickly and easily produce very high voltages. It can be used in conjunction with pith balls, Styrofoam peanuts, grounding rod, and Mylar balloons to demonstrate a buildup of static charge.

 

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Electric Fields & Potential


 

Hair on End

PIRA: 5B10.10

Description: This occurs when static electricity is induced on a person with the Van de Graaf machine. The person stores charged particles until they are released by touching something that is grounded.

 

Van de Graaff String Streamers

PIRA: 5B10.15

Description: The Van de Graaff with strings attached can show the direction of the electric field lines emanating from the dome. If a piece of the fur is placed on top of an uncharged Van de Graaff, once charged, the fur will fly off in the direction of the electric field. Styrofoam peanuts will behave similarly. When charged, the Van de Graff with strings attached displays the direction of the electric field lines emanating from the dome.

 

Grass Seed

PIRA: 5B10.41

Description: The grass seed suspended in oil can be used to show electric field lines around various configuration. The Van de Graaff can be used to supply a potential difference. The tray is set up on an overhead projector so the shadows of the seeds are seen lining up along the electric field lines.

 

Faraday Cage & Tesla Coil

PIRA: 5B20.11

 

Faraday Cage & Radio

PIRA: 5B20.15

 

Fluorescent Tube

PIRA: 5B30.15

Description: If a fluorescent tube is brought near a charged Van de Graaff, a potential difference across the tube will exist if the tube is held along a radius. The tube will light, showing that potential changes in the direction of the field. If the tube is held “tangent” to the Van de Graaff, no potential will exist between the ends so the tube won’t light.

 

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Capacitance


 

Capacitor Assortment

PIRA: 5C10.10

Description: A selection of capacitors can show that the size of the capacitor is not always related to the amount of capacitance.

 

Parallel Plate Capacitor and Electrometer

PIRA: 5C10.20

Description: Copper screen laid on the table is used as a common ground between the Van de Graaff and either the Leyden jar or the parallel plate capacitor. The discharge bar can be used to charge either capacitor. Once charged, either can be disassembled and reassembled. When reassembled, if discharged, a considerable spark is produced.

 

Variable Dielectric Capacitor

PIRA: 5C20.11

Description: A charge is placed on a plate of the variable capacitor. A dielectric can be moved between the plates and as the voltage changes it can be viewed using a Keithley Electrometer.

 

Leyden Jar Assortment

PIRA: 5C30.11

Description: The assortment includes, a large Leyden jar with a high capacitance. The large Leyden jar has a capacitance of 1100 pF. After being fully charged, the crack during discharge is quite impressive.

 

Blow up a Capacitor

PIRA: 5C30.15

 

Short a Capacitor

PIRA: 5C30.20

Description: Charge a large electrolytic (50,000 mfd) capacitor to 70V and short with a screwdriver.

 

Capacitor & Light Bulb

PIRA: 5C30.30

Description: Charge a large electrolytic (5000 mfd) capacitor to 120V and short it with a screwdriver. The sparks really fly. Also, charge the large electrolytic capacitor and connect it to a lamp. The bulb will glow brightly.

 

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Resistance


 

Rheostat & Light Bulb

PIRA: 5D10.42

Description: By using DC voltage with a rheostat and light bulb, the change in brightness of the bulb can be easily viewed. Increase resistance (dimmer) or decrease resistance (brighter).

 

Salt Tube with Multimeter

PIRA: 5D10.43

Description: A section of rubber tubing has been filled with a salt solution then sealed. The changing resistance with the “stretch” (change of length) can be viewed by using a multimeter.

 

Multimeter & Resistors

PIRA: 5D10.45

 

Fry Resistors

PIRA: 5D10.46

 

Superconductivity

PIRA: 5D10.47

 

Temperature Dependence with Liquid Nitrogen

PIRA: 5D20.10

Description: The two bulbs (carbon and tungsten) will show different temperature dependent resistance. The oscilloscope displays current vs. voltage for the bulbs.

 

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EMF & Current


 

Wet Cell

PIRA: 5E40.05

Fruit Battery

PIRA: 5E40.26

 

D-cell & light bulb

PIRA: 5E40.30

 

Light Bulb, D-cell & Galvanometer

PIRA: 5E40.31

 

Resistors, D-cell & Galvanometer

PIRA: 5E40.32

 

Electric Currents Laser Disk {D51,53}

PIRA: 5E40.40

 

Half of a Battery

PIRA: 5E40.50

 

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DC Circuits


 

Hot Dog Cooking

PIRA: 5F15.20

Description: Apply 110V through a hot dog and cook it.

 

Kirchhoff’s Voltage Law

PIRA: 5F20.10

Description: This law states that the total voltage summed around a circuit loop will equal the amount of voltage produced by the voltage source. A small board (can be put on overhead projector) is equipped with 2 batteries and various resistors.  The voltage rises and falls can be tested around the circuit to demonstrate Kirchhoff’s Voltage Law.

 

Potentiometer Circuit Board

PIRA: 5F20.31

 

Whetstone Bridge

PIRA: 5F20.40

 

Series Light Bulbs

PIRA: 5F20.50

Description: Three light bulbs are connected in series. The voltage and the current can be measured at any point in the circuit using a multimeter. The voltage and the current can be measured at any point in the circuit and displayed on an overhead projector.

 

Parallel Light Bulbs

PIRA: 5F20.51

Description: Three light bulbs are connected in parallel. The voltage and the current can be measured at any point in the circuit using a multimeter. The voltage and the current can be measured at any point in the circuit and displayed on an overhead projector.

 

Capacitor & Light Bulb

PIRA: 5F30.10

Description: Charge a large electrolytic capacitor and connect it to a lamp. The capacitor is discharged through the light bulb.

 

RC Time Constant

PIRA: 5F30.20

Description: A circuit with a slow time constant (.1-10sec) is charged and discharged and the current and voltage are displayed on the computer running DataStudio.

 

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Magnetic Materials


 

Magnetism Laser Disk {D60-69}

PIRA: 5G10.05

Magnet Assortment

PIRA: 5G10.10

Description: We have horse shoe, ceramic, rubber, and rod magnets. Also, there is a magnet with four poles. By using an overhead transparency and iron filings the magnetic field lines can be shown on the overhead projector.

 

Broken Magnet

PIRA: 5G10.21

Description: The broken magnet demonstrates that each piece of the magnet has North pole and a South pole.

 

Magnetron Magnet with Iron & Brass Rods

PIRA: 5G10.31

 

Magnetic Domain Model

PIRA: 5G20.30

Description: The magnetic domain model can be used to show the random yet ordered arrangement of atoms in magnetic material.

 

Cow Magnet & Iron Filings

PIRA: 5G20.31

 

3 – D Magnet

PIRA: 5G20.32

 

Electromagnet

PIRA: 5G20.71

Description: A piece of iron placed within a solenoid which results in the increase of the magnetic field. This magnetic field is the sum of that due to the current and that due to the iron. It is called soft because the magnetism it gains and loses occurs quite rapidly when the current is turned on or off.

 

Liquid Oxygen

PIRA: 5G30.11

 

Curie Point

PIRA: 5G50.10

Description: We have gadolinium rods which will display ferromagnetic properties until they are heated to 19 degrees C. At that point and above, they become paramagnetic.

 

Superconductivity (Meissner Effect)

PIRA: 5G50.50

Description: Place a small powerful magnet over a disc of superconducting material cooled to liquid nitrogen temperature.

 

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Magnetic Fields & Forces


 

Inclinometer

PIRA: 5H10.15

Description: A dip needle is used to show the inclination of the earth’s magnetic field.

 

Magnet , Iron Filings & Compass

PIRA: 5H10.30

Description: When a magnet is placed below a piece of paper and iron filings are scattered over the paper, lines of direction form. These polarity lines can reveal which direction the magnet is and which end is north and south with the use of the compass.

This reveals also the magnetic patterns induced by the poles of the magnet.

 

Magnet & Compass

PIRA: 5H10.31

 

3-D Magnet

PIRA: 5H10.33

 

Iron Filings Around a Wire {compass}

PIRA: 5H15.10

Description: We have a single wire loop, a six turn coil, a 15 turn coil and a solenoid. They demonstrate the magnetic field about loop(s) when a current passes through the coil(s). This can be easily done because the loop(s) are mounted in a piece of Plexiglas (for overhead projector viewing). After iron filings are sprinkled on the Plexiglas, the power source is turned on and the filings arrange in the field lines.

 

Iron Filings Around a 6 Turn Loop {compass}

PIRA: 5H15.11

Description: We have a single wire loop, a six turn coil and a 15 turn coil. They demonstrate the magnetic field about loop(s) when a current passes through the coil(s). This can be easily done because the loop(s) are mounted in a piece of Plexiglas (for overhead projector viewing). After iron filings are sprinkled on the Plexiglas, the power source is turned on and the filings arrange in the field lines.

 

Iron Filings Around a 15 Turn Loop {compass}

PIRA: 5H15.12

Description: We have a single wire loop, a six turn coil and a 15 turn coil. They demonstrate the magnetic field about loop(s) when a current passes through the coil(s). This can be easily done because the loop(s) are mounted in a piece of Plexiglas (for overhead projector viewing). After iron filings are sprinkled on the Plexiglas, the power source is turned on and the filings arrange in the field lines.

 

Current Carrying Wire & Compass

PIRA: 5H15.14

 

Solenoid & Iron Filings {compass}

PIRA: 5H15.40

Description: The solenoid can demonstrate the magnetic field about a solenoid when a current passes through the coils.

This can be easily done because the solenoid is mounted in a piece of Plexiglas (for overhead projector viewing). After iron filings are sprinkled on the Plexiglas, the power source is turned on and the filings arrange in the field lines.

 

Levitation Magnets

PIRA: 5H20.20

Description: Four magnets on a rod that levitate due to magnetic repulsion.

 

Electron Deflection on Laser Disk {D75}

PIRA: 5H30.05

 

Cathode Ray Tube in Crookes Tube

PIRA: 5H30.10

Description: Deflect the beam in an open CRT with a magnet.

 

Parallel Wires

PIRA: 5H40.10

Description: Demonstrates the force on current carrying parallel wires. They can show repulsion or attraction depending upon the direction of the currents in the wires.

 

Interacting Coils

PIRA: 5H40.15

Description: A narrow loop formed by hanging a flexible wire opens when current is passed. Two loops in proximity attract or repel depending on the current direction.

 

Jumping Wire

PIRA: 5H40.30

Description: A wire is placed in a horseshoe magnet and connected to a battery. A loop of lead wire connected to a power supply can be placed in the large magnetron magnet. When the power is turned on, the wire violently jumps out of the magnetic field.

 

Current Balance

PIRA: 5H40.40

Description: An open rectangle of aluminum wire is balanced between the poles of a “U” magnet until current is passed through the part perpendicular to the field.

 

Torque on a Current Loop

PIRA: 5H50.21

Description: A large loop is suspended over a magnet setting on a Lazy Susan for ease of adjusting the orientation of the magnet and loop.  Once the switch is thrown the loop will attempt to align itself into a position perpendicular to the field of the magnet.

 

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Inductance


 

LR Time Constant on Computer

PIRA: 5J20.10

Description: The current and voltage of a slow time constant LR circuit are displayed on the computer using DataStudio.

 

LRC Ringing

PIRA: 5J30.10

 

Inductive Kick Circuit

PIRA: 5J30.20

Description: This happens when a DC circuit with RC charging and RLC discharging occurs.

 

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Electromagnetic Induction


 

Galvanometer, Long Wire, & Magnet

PIRA: 5K10.15

Description: A straight wire connected to a galvanometer is moved rapidly through the poles of a strong magnet.

 

Induction Coil with Magnet & Galvanometer

PIRA: 5K10.20

Description: The coil and the galvanometer are connected.  As a magnet passes through the coil, an induced EMF is created and the galvanometer deflects show the presence of a current.

 

Wire Coil with Magnet, Galvanometer & Sledge Hammer

PIRA: 5K10.22

Description: A magnet is passed in and out of a copper coil hooked to a millivoltmeter and string loop hooked to an electrometer.

 

Flash Bulb (Use LED’s)

PIRA: 5K10.26

Description: By using the large magnetron magnet, sufficient current can be attained to “set off” a flash bulb. It consists of a wire coil and a flash bulb socket mounted to an aluminum plate.

 

Battery and Galvanometer

PIRA: 5K10.30

Description: Attach one coil to a galvanometer, another to a battery and tap switch. Use a core to increase coupling.

 

Induction Accelerator

PIRA: 5K10.31

Description: Two coils are wound on an iron ring, one connected to a galvanometer, the other to a battery and switch.

 

Magnetic Brake

PIRA: 5K20.11

Description: Various aluminum plates swing between the poles of a magnetron magnet. Some stop and some continue swinging.

 

Falling Magnet

PIRA: 5K20.25

Description: Drop a magnet and then a non-mangnetic dummy through a copper tube. The magnet falls slowly.

 

Jumping Ring

PIRA: 5K20.30

Description: A solid aluminum ring on the vertical transformer jumps while a split ring does not. The device is constructed of a large number of coils wrapped around an iron core.  It can either be plugged into an AC wall socket or connected to a large current power supply.  The iron core can be pulled up (partially) out of the coil and various rings put around the core.  When the switch is engaged, the metal rings will jump up a little (using DC power supply) or fly completely off the coil (when using the AC outlet).

 

AC Coils

PIRA: 5K30.61

Description: Light a light bulb with out it being attached to a power source. It consists of two coils, one coil is plugged into an AC outlet and the other is connected to the light bulb.

When the AC coil is plugged in and the other coil is brought close, the light bulb will glow brightly.

 

Motor

PIRA: 5K40.10

Description: A small electromagnetic motor shows how a simple motor is constructed and operated. The motor is a very simple motor with easy to see components.  It operates well at around 6 Volts.

 

Motor on Laser Disk{D74}

PIRA: 5K40.11

 

Generator

PIRA: 5K40.80

Description: Use the hand-crank generator to light an ordinary light bulb. A series of coils are rotated within a magnetic field by using a crank. A light bulb is connected to the unit. When the coils are rotated quickly, the light bulb begins to glow.

 

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AC Circuits


 

Sine Wave on the Computer

PIRA: 5L01.10

 

RC Circuit {Exponential Decay of a Capacitor}

PIRA: 5L10.31

Description: By using a function generator, a variable resistor, a variable capacitor and a variable inductor, phase differences can be shown at a range of frequencies and values of the constituent components.

 

LRC Resonance

PIRA: 5L20.20

Description: The same configuration of equipment for the RLC phase difference can be used to demonstrate the resonance frequency of the circuit.

 

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Electromagnetic Radiation


 

Tesla Coil

PIRA: 5N20.40

Description: The Tesla coil is a very good method of demonstrating the creation of high voltages.

 

Glowing Fluorescent Lamp

PIRA: 5N20.50

Description: Light a fluorescent light bulb is held in the Tesla coil radiation field.

 

Spectrum with a Prism

PIRA: 5N30.10

Description: Project white light through a high dispersion prism.

 

Electromagnetic Wave Model

PIRA: 5N40.10

 

Fluorescent Rocks

PIRA: 5N50.10

 

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