Magnetism Demonstrations

Magnetism arises from the movement of electric charges and is closely linked to electricity. This category explores magnetic fields, attraction and repulsion, and how magnets interact with materials. Understanding magnetism helps explain natural phenomena such as Earth’s magnetic field, as well as practical technologies that rely on magnets.

Demonstration	Materials	Difficulty	Safety	Summary
Electromagnetic Induction	★★☆	★☆☆	★☆☆	A bar magnet moved through a solenoid induces a voltage, detected by an electrometer. This demonstrates Faraday’s law of electromagnetic induction, showing how changing magnetic flux generates an electromotive force (emf).
Simple Electric Motor	★★☆	★★☆	★☆☆	A simple electric motor is built using a coil of wire, a battery, paperclips, and strong magnets. The motor works by converting electrical energy into mechanical motion through the interaction of a magnetic field from a permanent magnet and a temporary magnetic field created by current flowing in the coil.
Iron in Cereal	★☆☆	★☆☆	★☆☆	Blend cereal with water to make a slurry, then pass it by a strong magnet to collect supplemental iron particles.
Floating Needle Compass	★☆☆	★☆☆	★☆☆	By magnetizing a needle and floating it on cork in water, you can create a simple compass that aligns with Earth’s magnetic field and points toward the nearest magnetic pole.
Creating an Electromagnet	★★☆	★☆☆	★★☆	Insulated wire is wrapped around an iron nail and connected to a battery to create an electromagnet. Coil count and current are investigated using magnetic strength to pick up paperclips and move compasses.
3D Magnetic Field Demonstration	★★☆	★☆☆	★★☆	Iron filings suspended in a viscous liquid inside a clear bottle align along the magnetic field lines when exposed to a strong magnet, creating a visible three-dimensional representation of the field.
Magnetic Levitation with Pyrolytic Graphite	★★★	★★★	★★☆	Pyrolytic graphite is a strongly diamagnetic material that can levitate above neodymium magnets. It also conducts heat efficiently, allowing it to melt through ice easily by transferring heat from your hand.
Magnetic Fields with Iron Filings	★☆☆	★☆☆	★☆☆	This activity uses iron filings sprinkled over paper or a transparency placed on a magnet to reveal magnetic field patterns. The filings align themselves along invisible magnetic field lines, providing a visual representation of the field.
Model Electric Bell	★★☆	★★☆	★★☆	This demonstration models the principle of an electric bell using an electromagnet and a vibrating steel strip. When current flows through the coil, the strip is attracted, breaking the circuit. The strip then springs back, re-closing the circuit, and the cycle repeats to produce continuous vibration.
Lenz’s Law Tubes	★★☆	★☆☆	★☆☆	This demonstration shows Lenz’s Law using two similar cylinders, one magnetic and one non-magnetic, dropped through an aluminum tube. The magnetic cylinder falls much more slowly because eddy currents induced in the aluminum create a magnetic field opposing its motion.
Magnetic Force and Separation Distance	★★☆	★★☆	★☆☆	This experiment measures the force between two permanent bar magnets as their separation distance changes. Students collect data and plot graphs to investigate the mathematical relationship, which approximates an inverse square law but may follow a slightly different power law.
Electromagnetic Train	★★☆	★★☆	★☆☆	This project demonstrates the link between electricity and magnetism by creating a simple electromagnetic “train.” A battery with magnets attached is placed inside a copper wire coil. When the circuit is completed, the magnetic fields interact and propel the train through the coil.
Diamagnetism of Water	★★☆	★☆☆	★☆☆	Water is diamagnetic, meaning it creates a weak magnetic field opposite to an applied external magnetic field. This property can be demonstrated by the slight repulsion of water from a strong magnet.
Eddy Currents and Magnetic Damping	★★★	★★☆	★☆☆	When a conductor moves through a magnetic field, induced currents called eddy currents circulate within the material. According to Lenz’s law, these currents oppose the motion that produced them, creating drag known as magnetic damping. This effect is demonstrated with a pendulum swinging between magnet poles and has applications in braking, balances, and induction technologies.
Meissner Effect	★★★	★★☆	★★★	When cooled below its critical temperature using liquid nitrogen, a superconductor expels magnetic fields and becomes a perfect diamagnet. This phenomenon, known as the Meissner effect, allows a magnet to levitate above the superconductor until it warms above its transition temperature.

Materials
★☆☆ Easy to get from supermarket or hardware store
★★☆ Available in most school laboratories or specialist stores
★★★ Requires materials not commonly found in school laboratories

Difficulty
★☆☆ Can be easily done by most teenagers
★★☆ Available in most school laboratories or specialist stores
★★★ Requires a more experienced teacher

Safety
★☆☆ Minimal safety procedures required
★★☆ Some safety precautions required to perform safely
★★★ Only to be attempted with adequate safety procedures and trained staff