Circuits & Electromagnetism

Bin bag capacitor  (UK STEM video which shows how to introduce capacitors with a demonstration which uses a bin bag, aluminium foil , an EHT power supply and a centre-reading galvanometer. )

Bicycle Generator | Pūngao Paihikara (VUW Awhina resource with video)
A bicycle is used to spin a generator and power light bulbs.

Boil Up | Tōrua Korohuhū (VUW Awhina resource)
Electromagnetic induction is used to heat a copper ring and boil water.

Eddy Current Drag | Papa Konukura (VUW Awhina resource)
A strong rare Earth magnet and slabs of copper illustrate electromagnetic induction and eddy currents in dramatic fashion.

Eddy Current Tank | Te Taika Konukura (VUW Awhina resource)
A strong rare Earth magnet and slabs of copper illustrate electromagnetic induction and eddy currents in dramatic fashion.

Eddy Current Tubes | Ngā Ngongo Aurere (VUW Awhina resource)
A non-magnetic pellet falls quickly through a conducting aluminium tube but a magnetic pellet falls slowly.

Eddy Current Vanes | Haukapo Rā Aurere (VUW Awhina resource)
An aluminium vane swings slowly between the poles of a magnet while a plastic vane is unimpeded. A slotted aluminium vane swings at intermediate speed.

Electricity Generation | Te Mahi Hiko (VUW Awhina resource)
A primer on the generation and use of electricity in New Zealand.

Electricity Power Grid | Te Pūkawe Hiko Matua o Aotearoa (VUW Awhina resource)
A primer on New Zealand’s electricity transmission grid.

Faraday’s Law | Te Ture a Wharara (VUW Awhina resource)
Faraday’s Law of electromagnetic induction demonstrated with a coil and magnet.

Floating On Air | Pūkawekawe (VUW Awhina resource)
A superconducting disk is used to levitate a magnet, demonstrating the Meissner Effect.

Jumping Ring | Porohita Pēpeke (VUW Awhina resource)
Electromagnetic induction causes an aluminium ring to jump.

Transformers (VUW Awhina resource)
A primer on transformers and their use in the electricity distribution grid.

Trick Magnet | Autō Nuka (VUW Awhina resource)
One of two apparently identical steel rods passes easily between the poles of a magnet while the other unavoidably sticks to the magnet. One is stainless steel, the other mild steel.

Model Hydroelectric Generator | Hiko-ā-Awa (VUW Awhina resource)
A model hydroelectric generator powered by a garden hose operates a small light.

Model Windmill Generator | Pūrere Kapohau (VUW Awhina resource)
A model wind turbine generator powers a small light.

A Shocking Experience: The Van de Graaff Generator (VUW resource)
A Van de Graaff generator is used to make hair stand on end, generate sparks and so on.

Jumping Wire (VUW resource)
A wire carrying a DC current jumps up or down between the poles of a magnet depending on the directions of the current and magnetic field.

Floating Skier: A Levitating Superconductor (VUW resource)
A “skier” on a superconducting disk skies along a track by levitating above a magnetic strip. This is the reverse of the usual demonstration in which a small rare Earth magnet is levitated above as superconducting disk.

Levitating Magnet (VUW resource)
A magnet floats above a superconductor.

Electrical Properties of Superconductors (VUW resource)
Exploring electrical properties of superconductors using four-lead resistance measurements.

Microwaves (VUW resource)
A low-power apparatus is used to demonstrate the properties of microwaves. Detailed instructions are included for a number of experiments.

Bouncing Magnet (VUW resource)
A very large, very strong rare earth magnet is dropped onto a copper block cooled in liquid nitrogen. The magnet is seen to bounce “off the field” a few centimetres above the copper block. This surprising behaviour cannot be explained using Faraday’s law and Lenz’s laws as they are presented in secondary school textbooks alone. Why does the magnet bounce? High speed video shows the details of the motion. The effect is even more spectacular and more interesting when dropping a magnet on a superconductor.

Eddy Current Tubes (VUW resource)
A magnetic and non-magnetic pellet fall at the same rate in a plastic tube but not in an aluminium tube. What will happen with the slotted tube?

Thermal Generator (VUW resource)
Electricity generation with a Stirling engine.

Hand Generator (VUW resource)
Use a hand cranked generator to light a small light bulb.

Electric Pendulum (VUW resource)
A pendulum swings between two charged plates due to electrostatic forces.

Capacitor Spark (VUW resource)
Charge and discharge of capacitors, energy stored in a capacitor, high voltage safety.

Capacitor and Light Bulb (VUW resource)
A capacitor charges and discharges with a long time constant through a light whose brightness indicates the current.

Circuit Components (VUW resource)
A selection of circuit components shows the miniaturisation of electronics