Electricity and Magnetism

# Thumbnail Name Description
5A10.10 Click for full description Rods and Fur By rubbing the rods with the rabbit fur (or other cloths), a net charge is built up on the rod. You can show how small pieces of paper get attracted, among many other things (separate demos).
5A10.20 Click for full description Electrophorus Used to show the transfer of charge by induction using the Electrophorus.
5A20.20 Click for full description Charging Pith Balls (Induction) This demonstration illustrates Induction and Coulomb's law using a pith ball and the rods and fur.
5A22.10 Click for full description Braun Electroscope This shows how an electroscope works. When a charge is put on the top plate, it will repel the needle.
5A22.30 Click for full description Gold Leaf Electroscope This is a gold leaf electroscope. When a charged rod is brought near, the two leafs will repel each other because they acquire the same charge.
5A30.10 Click for full description Wire versus String This demonstration shows the difference between a conductor and an insulator.
5A40.20 Click for full description Attracted soda can (Induction) This demonstration illustrates induction in a metal soda can.
5A40.23 Click for full description Blow soap bubbles at Van de Graff This demonstration shows the induction of neutral soap bubbles when they float near the Van de Graff machine. Initially the bubbles are attracted to the charged dome, but as they get close, some charge leaks from the dome to the bubbles, giving them a net charge of the same sign as the dome, and they are quickly repelled away!
5A40.30 Click for full description Charged rod deflects 2 x 4 This demonstration shows induction by being able to rotate a large 2x4 piece of wood.
5A40.40 Click for full description Deflection of a stream of water This demonstration shows that a charged rod can deflect a stream of water.
5A50.10 Click for full description Wimshursts Machine This machine is used to create electric charge and store it in capacitors (Leyden jars). When the voltage is high enough for the charge to overcome the air gap at the electrodes, electrostatic breakdown occurs and a spark is seen and heard.
5A50.30 Click for full description Van de Graff Generator This is a high voltage Van de Graff generator (~400,000V) used for many electricity demos. If you put two grounding sources close together, you can change the frequency of discharges thus creating more powerful discharges.
5B10.10 Click for full description Hair on end This demonstration illustrates the buildup of charge on someone's hair.
5B10.15 Click for full description Van de Graff streamers Place the streamers on the Van de Graff machine. As the streamers get charged, they will follow the electric field lines.
5B10.25 Click for full description Styrofoam peanuts on Van de Graff generator This demo shows the buildup of charge on Styrofoam peanuts by the Van de Graff generator.
5B10.30 Click for full description Franklin's Bell (electric chimes) A conductive ball is suspended between two vertical parallel plates connected to the Wimshurst machine. The ball strikes one plate and obtains that charge; it is then repelled by that plate and is attracted to the other plate. The ball strikes the other plate, is discharged and obtains the charge of the plate it just struck, thus being repelled again. This sequence soon becomes very rapid and the ball begins to bounce from one plate to the other, sounding like a bell.
5B10.40 Click for full description Electric Field Lines on overhead This demonstration visually shows the electric field lines using the overhead projector.
5B10.51 Click for full description Mapping Equipotential lines This demonstration uses a voltage probe to view equipotential voltage lines. Designed to be used on the overhead projector.
5B20.10 Click for full description Surface Charge This demo shows that charge on a solid conductor resides entirely on the outer surface. This is commonly referred to as Faraday's Icepail Experiment and is also the principle of the Van de Graff generator.
5B20.35 Click for full description Faraday Cage Radio waves, being electromagnetic in nature, do not penetrate the metal cage because the cage acts as a vertical and horizontal polarizer. Since radio waves do not enter the Faraday cage, the radio will loose reception.
5B30.35 Click for full description Point and ball with Van de Graff This demonstration illustrates how a lightning rod works (as well as any sharp point).
5B30.50 Click for full description Electrostatic Pinwheel This demonstration shows that a pinwheel on a Van de Graff generator will spin.
5C10.10 Click for full description Sample Capacitors This demonstration shows students the wide variety of capacitors and how different they look.
5C10.20 Click for full description Parallel Plate Capacitor This demo uses a large parallel plate capacitor to show that the capacitance varies when the air gap size is changed.
5C20.10 Click for full description Capacitor with Dielectrics This demo illustrates the effects of a dielectric on a capacitor.
5C30.20 Click for full description Short a Capacitor This demo shows what happens when you short a large capacitor.
5C30.30 Click for full description Light the Bulb This demonstrations shows that a large capacitor can light a bulb for several seconds.
5C30.60 Click for full description Residual Charge Charge up a Leyden jar and discharge it. Wait a few seconds and then discharge it again. Currently not very effect. We are working on a better demo setup.
5D10.40 Click for full description Resistance Model This is a visual model of resistance on a microscopic scale. When the lead ball hits a nail, this represents resistance to the flow of the "electron".
5D20.10 Click for full description Wire coil in LN2 A wire coil is connected in series to a battery and light. When the wire coil is put in the Liquid Nitrogen, the light bulb will become brighter. The wire coil's resistance decreased.
5D20.20 Click for full description Wire coil in Flame A wire coil is connected in series to a battery and light bulb. When the wire coil is heated up in the flame, the light bulb becomes dimmer. The wire coil's resistance increased.
Click for full description
Jacob's Ladder The Jacob's Ladder uses AC voltage with a transformer made of two wire coils in such a way to step up the voltage. With an initial gap of about 1cm at the bottom, ~10,000Vac should create an electric arc that rises to the top of the two metal rods. This process repeats itself.
5E40.20 Click for full description Voltaic Cell A voltaic cell is made with copper and zinc electrodes in a sulfuric acid solution.
5E40.25 Click for full description Fruit and Vegetable Battery This demonstration uses the energy of two fruit to power a clock.
5E50.65 Click for full description Thermoelectric Fan (Peltier) By keeping the plates of a peltier at different temperatures, a current is produced to run the fan.
5F10.15 Click for full description Water Analog (voltage drop and current) This is a visual model of a voltage drop and the current. You may adjust the height of the water bottle to show a change in voltage, and thus current.
5F15.20 Click for full description Hot Dog Cooker To show power and energy, apply 120VAC through a hot dog to cook it.
5F15.32 Click for full description Vaporize a wire Short a car battery with a wire to burn it. The car battery is able to supply over 100amps of current for a short time.
5F20.50 Click for full description Series and Parallel Lights This configuration shows a set of series and a set of parallel lights connected to AC voltage. Other things can be shown, such as what happens when you remove a light bulb, or use different wattage bulbs.
5F30.20 Click for full description Charge and discharge an RC circuit Use the oscilloscope to show V(t) for a capacitor charging and discharging in an RC circuit.
5G20.30 Click for full description Magnetic Domains (array of arrows) This demo shows the magnetic field lines of a magnet on the overhead projector.
5G20.70 Click for full description Small Electromagnet This demonstration uses a small electromagnet connected to a 9V battery to pick up the nails. You can also show if the electromagnet exhibits hysteresis.
5G20.71 Click for full description Electromagnet This demonstration illustrates the pieces that make up a simple electromagnet.
5G30.20 Click for full description Paramagnetism of liquid oxygen Using a high power magnet, you can show the paramagnetism of liquid oxygen In general, liquid oxygen is not magnetic, but when an external magnetic field is introduced, the dipole moments give the material a net magnetic field.
5G50.10 Click for full description Curie point A ball of iron is attached to a magnet. Heat the iron near the magnet and it should fall after a few seconds.
5G50.50 Click for full description Meissner effect Cool a superconductor with liquid nitrogen and a small magnet floats on it due to magnet repulsion.
5H10.30 Click for full description Magnetic field lines (iron filings) This demo shows the magnetic field lines of a magnet on the overhead projector.
5H15.10 Click for full description Iron Filings Around a Wire Iron filings are sprinkled around a vertical wire running through plexiglass. The iron filings align themselves with the magnetic field caused by the current in the wire.
5H15.40 Click for full description Iron Filings Around a Solenoid A solenoid is wound through a peice of plexiglass for use with iron filings on the overhead projector. The iron filings align themselves with the magnetic field caused by the current in the solenoid. (Also see 5H15.10)
5H20.10 Click for full description Magnets on a pivot This demonstration shows that a magnet on a pivot will move in response to another magnet close by. A variation of this is to put both magnets on a pivot and observe that opposite poles attract.
5H30.10 Click for full description Magnet and TV This demonstration shows what happens when you bring a magnet near a CRT. The magnet bends the electron beam so the electrons no longer hit the correct phosphors on the screen, which messes up the colors.
5H30.15 Click for full description Bending an Electron Beam This demonstration shows that a magnetic field can deflect a beam of moving electrons.
5H30.22 Click for full description Magnetic deflection of cathode rays (e/m tube) A beam of electrons is propelled vertically. When a current is sent through the Helmholtz coils, a magnetic field is established perpendicular to the direction of the electron beams and thus deflects the electrons (See picture). Depending on the magnitude of the magnetic field, the beam can range from slightly bent to a full circle.
5H40.10 Click for full description Parallel Wires (pinching wires) This demonstration shows the interaction of current passing through parallel wires. The wires will pinch (parallel current), while the tin foil will spread apart (anti parallel current).
5H40.30 Click for full description Jumping Wire This demonstration shows the interaction between the moving current in a wire in the presence of a magnetic field.
5H40.71 Click for full description Rolling rod (Ampere's motor) This demonstration visually shows the interaction between a magnetic field and a current carrying rod.
5H50.20 Click for full description Force on a Current loop This demonstration shows the force on a current carrying wire loop in a magnetic field.
5J10.20 Click for full description Inductance Spark (back EMF) This demonstration shows that the current stored in an inductor will take the path of least resistance, in this case the small air gap between the SPST switch when it is opened.
5J30.10 Click for full description RLC ringing (LCR trombone) The point of this demo is to show that an LCR (inductor-capacitor-resistor) circuit is a damped harmonic oscillator. When you give it a kick it oscillates for a while at the frequency omega=2*pi*f=(LC)^-1/2 but the oscillations die out due to dissipation in the resistor. In this demo, the resistance of the coil provides the R - there is no separate resistor, and the square wave provides periodic kicks. With each kick, the damped oscillations can be heard as a distinct note, and as the frequency is varied (by sliding the iron core in and out to change L) the note changes.
5K10.20 Click for full description Induction coil with magnet and galvanometer This demo shows that a moving magnetic field induces a current in a coil of wire, which can be displayed on an overhead projector. It also shows that the direction of the moving magnetic field determines the flow of current.
5K10.27 Click for full description Faraday's Flashlight This is a "Faraday's Flashlight" as seen on TV. A magnet moves up and down inside a coil of wire. Current is induced and forced into a capacitor (direction of the moving magnet does not matter). The LED runs off the capacitor.
5K20.10 Click for full description Eddy current Pendulum This demonstration shows the dampening force of a magnet on different discs. A pendulum is made to swing between the poles of an electromagnet. When the electromagnet is turned on, discs which allow for eddy currents will be damped, while those that do not allow eddy currents will not stop as fast.
5K20.20 Click for full description Eddy currents in a paddle When the conductive paddle is moved in the magnetic field, induced current loops (eddy currents) are produced. This induced current interacts with the magnetic field to produce an opposing force. Work must be done to overcome this opposing force. Electrons in the paddle swirl around to produce thermal energy.
5K20.25 Click for full description Magnets and Eddy Tubes This demonstration shows the difference eddy currents have on a falling magnet in a tube. The non magnet will fall down the tube quickly. Repeat with the magnet and it will take much longer.
5K20.30 Click for full description Jumping ring This demo shows how an aluminum ring can float around a vertical inductor. If enough current is applied, the ring will "jump" off the vertical inductor due to opposing magnetic fields.
5K30.20 Click for full description Transformers By coupling two coils to each other a transformer is created.
Connect the primary to an AC power supply and read off the voltage of the secondary. Can be used to show a step up or step down transformer.

5K40.10 Click for full description DC motor This demonstration visually shows the interaction between magnets and coils when a current is sent through the coils.
5K40.80 Click for full description Hand Crank Generator This demo shows a hand crank generator used to light up a bulb.
5L10.10 Click for full description Variable Inductance (Dimmer) This demonstration shows that a variable inductor connected in series with a light bulb will dim as the inductance is increased.
5L30.36 Click for full description High Pass / Low Pass Filter This demonstration allows students to see the effects an inductor and capacitor have on an AC source.
5N10.90 Click for full description EM wave production
(Mad scientist Radio)
An electrostatic generator creates EM waves that can be viewed on the oscilloscope.
5N20.10 Click for full description Induction coil This is a very old tesla coil.
5N20.25 Click for full description Hand Held Tesla coil This is a portable tesla coil. Can be used as any other tesla coil.
Click for full description Tesla Coil
Tesla coil and Fluorescent Light
Electrodeless Discharge
Tesla coil and Skin Effect
This demo uses a tesla coil to illuminate a fluorescent light bulb The high frequency and high voltage will actually excite the gas in the fluorescent tube.