Electricity and Magnetism (D)

Capacitance (D+0)


  D+0+0 Attraction between horizontal plates of a charged capacitor.
  D+0+1 Attraction between plates of a capacitor causes attachment of plates when insulator is introduced.
  D+0+2 Various capacitors to show.
  D+0+4 Parallel plate capacitor with dielectric materials and electroscope.
  D+0+5 Force on a dielectric in a capacitor
  D+0+6 Capacitor doorbell driven by Van de Graaff generator.
  D+0+8 Series capacitor array.
  D+0+10 Parallel capacitors array: A charged capacitor charges the others.
  D+0+12 Visual charge/discharge of a capacitor through a load.
  D+0+14 Computer demo: Charge/discharge of a capacitor, runs at least 1 min.
  D+0+16 Discharging a capacitor through a lamp.
  D+0+18 Capacitors with a series neon bulb on A.C. and D.C.
  D+0+20 Capacitor in series in an audio circuit: High pass filter.
  D+0+22 Effects of changing a D.C. voltage in a series RC circuit.
  D+0+24 Capacitor in parallel in an audio circuit: Low pass filter.
  D+0+26 Capacitor in parallel in a D.C. circuit.
  D+0+28 Energy storage in a commercial capacitor. Loud bang!
  D+0+30 Oscillator made with resistor, capacitor and neon lamp.
  D+0+34 Same as D+0+30 using oscilloscope to display waveform.

Electromagnetic Oscillations (D+5)


  D+5+0 Resonance in a series LCR circuit using 120 v.a.c.
  D+5+1 LCR paradox
  D+5+2 LCR series resonance curve of V vs. F (2 - 20kHz) on an oscilloscope.
  D+5+4 High frequency filtering using a capacitor and inductor.
  D+5+6 Crystal radio circuit for AM reception.
  D+5+8 Damped oscillations in a resonant LCR circuit on an oscilloscope.
  D+5+10 85 MHz radio transmitter, with indicating lamp on dipole antenna.
  D+5+12 Seibt effect: Wire wound glass tube with 510 transmitter.
  D+5+14 Standing waves on two parallel wires, with 510 transmitter.
  D+5+16 Lodge's experiment: Spark gap radio transmitter and receiver.
  D+5+18 3 cm. microwave klystron oscillator with cavity and waveguides.
  D+5+20 3 cm. microwave transmitter and receiver.
  D+5+22 Magnetron assembly to show.
  D+5+24 Waveguide pieces to show.
  D+5+26 Standing waves (micro or sound) in an adjustable cavity.
  D+5+28 AM and FM Demonstration(minimum 24 hr notice required).
  D+5+30 Wall chart of electromagnetic spectrum.
  D+5+32 Plexiglas model of electromagnetic wave.
  D+5+34 LEDs oscillate in stored energy LC circuit.

Electrostatics (D+10)


  D+10+0 Electric fields: Lines of force shown on an OHP.
  D+10+2 Transparency: Mapping of an electric field.
  D+10+4 Pith balls on thread, with positive and negative charged rods.
  D+10+6 Attraction and repulsion of charged styrofoam balls.
  D+10+8 Braun and Leaf electroscopes.
  D+10+9 Discharging an electroscope through ionization
  D+10+10 Faraday's ice pail: Charge induced on the outside of a pail.
  D+10+11 Alternate charge resides on outside of conductor
  D+10+12 Charge resides on the outside of a conductor.
  D+10+13 Faraday cage: blocks signal from portable radio
  D+10+14 Charging an electroscope by induction.
  D+10+16 Separation of charge using electrical tape and an electroscope.
  D+10+18 Electrophorous: Cat fur on teflon, acetate on lucite.
  D+10+20 Van de Graaff generator.
  D+10+22 Wimshurst machine, large or small.
  D+10+24 Electrostatic pinwheel:Van de Graaff makes pinwheel spin.
  D+10+25 Like Charges Attract
  D+10+26 Various Leyden jars to show.
  D+10+28 Electrostatic doorbell: Ball bangs between charged plates.
  D+10+30 Kelvin water drop electrostatic charge generator.
  D+10+35 Electric field created by Van de Graff splits ions in flame
  D+10+40 Applet: Charges and Fields

Faraday's Law (D+15)


  D+15+0 Bar magnet induces current in a coil, shown on galvanometer.
  D+15+1 Oscillating magnets in coupled coils
  D+15+2 Elementary generator: Bar moved in magnetic field.
  D+15+4 Earth inductor: Coil spun in Earth's field makes voltage.
  D+15+6 Generator: Coil with DC commutator rotates between magnets.
  D+15+8 Alternator: Coil with AC commutator rotates between magnets.
  D+15+10 Hand-cranked AC alternator powers 120 volt lamp.
  D+15+11 Hand-cranked DC generator powers 120 volt lamp.
  D+15+12 Back EMF in a series DC motor with large flywheel.
  D+15+14 Eddy currents: Copper disk rotates over a spinning bar magnet.
  D+15+16 Damped pendulum: Swinging metal disks damped in magnetic field.
  D+15+19Jumping Rings with AC or DC driving
  D+15+20 Jumping rings: High current AC coil causes rings to jump.
  D+15+22 Skin effect: Metal sheet shielding varies with frequency.
  D+15+24 Levitator: Aluminum dish floats four inches off platform.
  D+15+26 Eddy currents:Small magnet slowly drops between aluminum rails.
  D+15+28 Eddy currents: Neodymium Magnet Drop.
  D+15+30 Demonstration of dependence of number of coils on induced flux
  D+15+35 Equivalence of large and small loops around enclosed flux
  D+15+40 Flux through loop. EMF depends on position of the meter?
  D+15+45 Magnet inserted and withdrawn from copper ring causes ring to swing

Inductance (D+20)


  D+20+0 Energy stored in large coil with soft iron core flashes bulb.
  D+20+2 LR time constant: Square wave drives series LR on oscilloscope.
  D+20+4 AC dimmer: Soft iron core in coil dims lamps.

LCR Phase Relationships (D+25)


  D+25+0 Phases of V and I in series circuit as RL shifts to RC.

Magnetic Fields (D+30)


  D+30+0 Suspended magnetic lodestone on string.
  D+30+1 Large compass needle on stand.
  D+30+2 Dip needle compass.
  D+30+4 Earth model with internal magnet and pivoting probe magnet.
  D+30+6 Iron filings and permanent magnets to show field on an OHP.
  D+30+8 Compass needle shows field around a high current wire on bench top.
  D+30+10 Iron filings around a high current vertical wire on OHP to show field.
  D+30+12 Iron filings around a current carrying coil on OHP to show field.
  D+30+14 Magnetic field around a solenoid with pivoting probe magnet.
  D+30+16 Ampere's law: Currents in parallel wires attract or repel.
  D+30+18 Force on a current carrying wire in a magnetic field.
  D+30+20 Elementary motor: Bar on rails over solenoid with core.
  D+30+22 Torque on coil suspended between two magnets.
  D+30+24 Vacuum tube with screen shows cathode rays bent with a magnet.
  D+30+25 Elementary motor: De La Rive Tube.
  D+30+26 E/M tube: Circular bending of an electron beam in a magnetic field.
  D+30+28 Hall effect: Magnetic field induces a voltage in a neon plasma.
  D+30+30 Force on current carrying wire in a magnetic field
  D+30+31 Electromagnet with removable core

Magnetic Properties (D+35)


  D+35+0 Wobbly bar: Magnets in frame balanced by repulsive forces.
  D+35+1 Inverter Magnet
  D+35+2 Making a magnet by electromagnetic induction.
  D+35+4 Making small magnets by breaking up a larger magnet.
  D+35+6 Barkhausen effect: Magnet and coil with soft iron core.
  D+35+7 Barkhausen effect model: Many tiny magnets on pivots on OHP.
  D+35+9 Para and diamagnetic materials in magnetic field with OHP.
  D+35+10 Para and diamagnetic materials in magnetic field with arc lamp.
  D+35+12 Linear motor: An iron core jumps into a solenoid.
  D+35+14 YBaCuO pellet with magnet in liquid nitrogen on TV camera.
  D+35+15 Mass Driver
  D+35+16 Mass driver: One of these balls is not like the other
  D+35+20 Curie temperature

Meters (D+40)


  D+40+0 Tangent galvanometer: Compass needle pivots in a coil.
  D+40+2 Elementary galvanometer: Coil on spring in magnetic field.
  D+40+4 Mavometer: Ammeter / voltmeter / galvanometer
  D+40+6 Various meters for display.
  D+40+8 Ammeter shunt: Only a small current flows to the meter.

Motors (D+45)


  D+45+0 Rolling bar motor: Same as D+30+ 20.
  D+45+2 Elementary split-ring armature DC motor. D+15+6 as a motor.
  D+45+4 AC induction motor: Armature in a whirling field.
  D+45+6 Elementary motor: Electron beam revolves in magnetic field.
  D+45+8 Elementary motor: Magnet, wire and battery make a simple motor.
  D+45+10 Elementary motor: Magnets and battery and copper coil make a simple motor.
  D+45+11 Simple motor rolls straight and in circle

Oscilloscopes (D+50)


  D+50+0 The Braun tube with magnetic and electrostatic deflection.

Resistance (D+55)


  D+55+0 Resistance boards: Series, parallel, Wheatstone bridge.
  D+55+2 Watt's law: Variable resistor, glow coil, volt and amp meter.
  D+55+4 High current melts the fuse wire.
  D+55+5 Conductivity of solution with free ions
  D+55+6 Resistance thermometer: Iron coil in liquid Nitrogen and flame varies current.
  D+55+8 Effect of temperature on current in carbon or tungsten filaments.
  D+55+10 Large tungsten filament lamp; as it heats, current drops.
  D+55+12 Oscillator with resistor, capacitor and neon lamp.
  D+55+13 Same as D+55+12 using speaker for audio tone generation.
  D+55+14 Same as D+55+12 using oscilloscope to display waveform.
  D+55+16 Film: "Elementary electricity", sound; 8 min.
  D+55+18 Resistor analog: Marbles cascading down pin board.

Solid State and Semiconductors (D+60)


  D+60+0 P-N Junction as a rectifier: Current flows one way.
  D+60+2 P-N Junction as a rectifier: Diode bridge rectifies AC voltage.
  D+60+4 Photoelectric effect: Light on P-N junction causes current flow.
  D+60+6 Several commercial solar cells.
  D+60+8 Commercial solar cell spins propeller using small arc lamp.
  D+60+10 Impact on piezo-electric device flashes neon bulb.

Thermionic Emission (D+65)


  D+65+0 Edison effect: Electrons are cast off from hot filament.

Thermoelectricity (D+70)


  D+70+0 Thermocouple and thermopile, both make electricity from heat.
  D+70+2 Thermocouple magnet: Flame with water cooling holds weight.
  D+70+4 Thermocouple magnet: Flame with ice bath, holds weight.
  D+70+6 Thermoelectric fan: Fan runs off of hot and cold water.
  D+70+8 Peltier junction: Forward current freezes water drop, reverse boils.

Transformers (D+75)


  D+75+0 Demountable transformer with many secondary coils from 10:1 to 1:46.
  D+75+1 Same as above: Secondary used for spot-welding.
  D+75+2 Same as above: Secondary used for induction melting.
  D+75+3 Same as above: Secondary used for small Jacob's ladder.
  D+75+4 Large Tesla coil. 15 inch discharge.
  D+75+6 Automobile coil makes a spark.
  D+75+8 Large Jacob's ladder.

Voltaic Cells (D+80)


  D+80+0 Copper nail and iron nail in a lemon using a multimeter.
  D+80+4 Gotham cell: Assorted metal electrodes in sulfuric acid bath.
  D+80+6 Storage cell: Gotham cell is charged up and rings a bell.

Electrolysis (D+85)


  D+85+0 Electrolysis of water produces hydrogen and oxygen.
  D+85+2 Bubble Electrolysis.