Electricity and Magnetism

Zoom image: 3D magnetic field viewer The 3D magnetic field viewer contains iron filings suspended in an oil inside a 3" x 3" acrylic cube.

3D magnetic field viewer

Zoom image: Electric charge Various rods, clothes, pith balls and an electroscope can be used to show properties of electric charge.

Electric charge

Zoom image: Electron beam tube A beam of electrons can be deflected by a magnet to demonstrate the motion of charged particles in a magnetic field.

Electron beam tube

Zoom image: Flying rings Solid metal rings placed on the extended iron core of an AC solenoid will float in the air due to Lenz's law, whereas rings with a slot cut through them will not.

Flying rings

Zoom image: Homopolar motor A simple homopolar motor consists of a neodymium magnet, an AA battery, and a loop of copper wire. When assembled, the wire loop starts rotating due to the Lorentz force on charge carriers.

Homopolar motor

Zoom image: Magnetic field around a wire A compass placed near a current carrying wire will deflect due to the magnetic field produced around the wire.

Magnetic field around a wire

Zoom image: Metal detector A metal detector creates a time varying magnetic field in a coil, which in turn induces magnetic fields in nearby conductors. The induced field is picked up through a receiver coil.

Metal detector

Zoom image: Paramagnetism of liquid oxygen A small amount of liquid oxygen can be produced by inserting a metal tube that is sealed at the bottom inside a liquid nitrogen bath. When liquid oxygen is poured between the poles of a horseshoe magnet, it will stick due to its paramagnetic properties.

Paramagnetism of liquid oxygen

Zoom image: Solenoid inside another solenoid A smaller solenoid is inserted into the bore of a larger solenoid. When AC current is ran through the smaller solenoid by a hand-crank generator, the ammeter connected to the larger solenoid registers current due to Faraday's law.

Solenoid inside another solenoid

Zoom image: Transformer An air core step down transformer can be used to demonstrate properties of transformers. The primary winding is connected to 120 V AC. There is a light bulb connected as the load to the secondary winding, which steps input voltage down to 9 V AC.


Zoom image: Capacitors Various capacitors for showing students the different sizes, shapes and specifications they come in.


Zoom image: Electric fields A thin transparent container of fibers suspended in oil is placed on parallel metal plates. A hand crank electrostatic generator is used to charge the plates to a high potential. Fibers will align themselves with the electric field lines around the plates.

Electric fields

Zoom image: Faraday cage A radio placed inside a metal cage loses reception, demonstrating that electromagnetic radiation is blocked by a Faraday cage.

Faraday cage

Zoom image: Hand crank generator A 12 V hand crank generator can be used to demonstrate how generators work.

Hand crank generator

Zoom image: Lenz's law A magnetic and non-magnetic cylinder will fall through metal pipes at very different rates due to Lenz's law.

Lenz's law

Zoom image: Magnetic field of solenoid & toroid Small compasses are placed inside a solenoid and a toroid to demonstrate the magnetic field inside them.

Magnetic field of solenoid & toroid

Zoom image: Mini Lenz's law This is a smaller version of the Lenz's law demo. It can be demonstrated through the document viewer in lecture halls. A magnetic and non-magnetic cylinder will fall through 1/2" copper pipes at very different rates due to Lenz's law.

Mini Lenz's law

Zoom image: RL circuit The circuit consists of a solenoid connected to a light bulb. As an iron core is inserted inside the solenoid, its inductance increases. As a result, the voltage across the solenoid also increases, and the light bulb gets dimmer.

RL circuit

Zoom image: Superconductivity A small magnet is placed on a YBCO disk, and the disk is cooled below 93 K using liquid nitrogen. The magnet will start floating above the disk when it becomes superconductive, demonstrating the Meissner effect. Flux pinning can also be demonstrated by floating a cold YBCO disk over a track made of magnets.


Zoom image: van de Graaff generator A van de Graaff generator can be used to demonstrate properties of electric charge.

van de Graaff generator

Zoom image: Coulomb balance A Coulomb balance can be used to study the force between charged objects. It consists of a conductive sphere that slides on a rail, and another conductive sphere placed on a thin wire that can twist in response to the electrical force. The spheres are charged using a HV power supply.

Coulomb balance

Zoom image: Electric motor A 12 V DC two pole motor can be used to demonstrate the working principles of an electric motor.

Electric motor

Zoom image: Faraday's law 3 solenoids with different numbers of turns are connected to an ammeter. A magnet approaching to or receding from a solenoid will cause deflections in the ammeter, demonstrating Faraday's law.

Faraday's law

Zoom image: Hand held Tesla coil The hand-held Tesla coil produces up to 45 000 V at 500 kHz. It can be used to demonstrate dielectric breakdown of air and other materials.

Hand held Tesla coil

Zoom image: Lorentz force A current carrying wire inside a magnetic field will deflect due to the Lorentz force on charge carriers.

Lorentz force

Zoom image: Magnetic field viewing film The magnetic field viewing film contains tiny nickel flakes inside microcapsules. The flakes orient themselves so that the film appears black near magnetic fields.

Magnetic field viewing film

Zoom image: Parallel plate capacitor A parallel plate capacitor demo can be used to demonstrate properties of capacitors. The separation of the plates is adjustable, and various dielectric materials can be placed between them. The plates have about 220 pF of capacitance when they are closest, with no dielectric in between.

Parallel plate capacitor

Zoom image: RLC circuit An AC RLC circuit can be used to demonstrate resonance in RLC circuits. An iron core inserted into the solenoid bore will change the value of L. At resonance, the light bulb in the circuit will be the brightest.

RLC circuit

Zoom image: Tesla coil The Tesla coil can be used to demonstrate properties of resonant transformer circuits, as well as the dielectric breakdown of materials.

Tesla coil

Zoom image: Vernier circuit board Various R, L and C circuits can be built on the Vernier circuit board.

Vernier circuit board