Electricity and Magnetism Demos


Electric charge and field

Electroscopes
A qualitative measure of the charge on an object. (*)

Van de Graaff Generator
Produces over 200,000 V and can be used for a variety of electrostatic experiments.

Electrostatic Pendulum – Charging by Induction
Conducting sphere bounces back and forth due to charging via induction.

Electric Field Inside and Outside of a Sphere
Uses the Van de Graaf, a hollow sphere, and an electroscope to show that charge accumulates on the outer surface of the sphere, but not inside.

Electric Field Inside and Outside of a Cylinder
Shows that any excess charge is located entirely on the outer surface of a conductor.

Electric Field Apparatus
Displays electric field lines between two probes, plates, or concentric circles.

Parallel Plate Capacitor
A large parallel plate capacitor with variable distance between the plates.

Variable Capacitor
Capacitor showing variable capacitance, controlled by rotating, overlapping metal plates.

Whimshurst Machine
A large electrostatic generator.


Electric voltage and current

Parallel and Series Circuits
Up to 5 lamps can be connected in series or parallel and display the properties of these circuits.(*)

RC Charge and Decay                                                                                                       Displays the charge and discharge of a capacitor on an oscilloscope.(*)

RL Circuit
Shows how an RL circuit responds to positive and negative square pulses.

Low-Pass and High-Pass Filters
This demo shows how rearranging components in RL/RC circuits can create low-pass or hi-pass filters.

RLC Resonance                                                                                                        Demonstrates oscillations of energy between a capacitor and inductor.

Various Voltage Sources
Shows how chemical reactions, light and heat can be converted to electrical energy


Magnetism

Magnetic Field Demo
Displays the magnetic field of permanent magnets.(*)

Distribution of Magnets in a Uniform Magnetic Field
Magnets align themselves in a uniform magnetic field according to the law of minimal potential energy.

Compasses & Magnetic Inclination Apparatus
There are 5 small compasses and a big vertical compass to show the magnetic inclination.

Curie Point
Two demonstrations are available to show Curie Points for Iron and Gadolinium.


Electromagnetism

Electron Beam Deflection
Crookes tube is used to demonstrate magnetic and electrostatic deflection of an electron beam.

Magnetic Field About Wire
2 or 4 compasses are used to show the magnetic field generated by current in a wire.

Magnetic Field of Parallel Currents
Demonstrates magnetic attraction or repulsion of parallel currents.

Ampere Force
Force on a current-carrying wire in a magnetic field.(*)

Faraday’s Law — Electromagnetic Induction
A scope is used to show the effect of a magnet being dropped through a coil

Induced Magnetic Fields (and their energy)
Magnetic properties of a current-carrying coil, energy stored in a magnetic field, and mutual inductance can be demonstrated.

Lamp in Series with Inductance (Lenz’s Law)
Full brightness of a bulb in series with a large inductance is delayed for about one second in comparison to the bulb in a parallel circuit. If the iron core is removed from the coils, no delay is observed.

Wonder Tubes (Lenz’s Law) 
Magnet/non-magnet cylinders dropped simultaneously into aluminum tubes fall at different speeds.

Jumping Ring (Lenz’s Law)
A coil with an iron core and two aluminum rings is used to demonstrate electromagnetic induction and Lenz’s Law.

Eddy Current Pendulum
Solid, flat, pendulum bob is slowed when it passes between magnetic poles. Bob containing slits oscillates freely.

Transformer
Coils with different number of turns allow the instructor to set up several step-down and step-up circuits.

Motor-Generator
A simple, large model can be used to generate current or to work as an electric motor.

Bicycle Generator
A bicycle with gears attached to an electric generator powers 3 headlights that can be turned on successively.

RLC Resonance
Parallel and series RLC circuits of variable resonance frequencies are available.

Jacob’s Ladder
Electric arcs continuously rise between two vertical conducting bars.

Tesla Coil
Homemade 1.2 million Volt Tesla coil generates long lightning-like sparks.(*)

Electron Velocity Selector; Finding e/m Ratio
Motion of electrons in uniform electric and magnetic fields (and their combination) is demonstrated with a specially designed electron tube placed between Helmholtz coils.

Moving Electric Charge in a Magnetic Field. Lorentz Force 
Three demonstration are available. Spiraling electrons, Determination of e/m ratio, and Van Allen radiation belts.

Homopolar Motor (Mini Lorentz Force)                                                                                      Use a small AA battery, magnet, and copper winding to show the Lorentz force cause rotation


Quantum Effects

Photocell
Shows an application of the inner photoeffect. A photocell illuminated by a bright light source generates enough current to run a small DC motor.

Cathode Ray Emission
Electrons are accelerated through a cathode ray tube and fluorescence is observed. A magnet can be used to deflect the electron beam.

Photoelectric Effect
This demonstration qualitatively shows the discharging of a negatively charged metal plate under UV radiation.

Fluorescent materials
Various rocks fluoresce under UV light.

Maltese Cross Electron Tube
Shadow of a metal cross cast by a broad electron beam demonstrates the particle properties of electrons.

Electron Diffraction Apparatus
The electron gun projects a narrow beam of electrons through a thin layer of graphitized carbon onto a fluorescent screen.

Superconductivity
Induced current in superconducting disk causes magnetic field that repels a small magnet and forces it to levitate.

Piezoelectric Effect
Lead titanate crystal creates small electric charge when compressed.

Quantum Mechanics of Diodes
Displays several diodes in action to visualize the diode in action.