Electricity Demonstrations

See also: Van de Graaff Generator

Electricity is the flow of electric charge and is one of the most widely used forms of energy. This category introduces the principles of electric circuits, current, and voltage. Studying electricity builds an understanding of how devices work and how energy is transferred in systems that power modern life.

Demonstration	Materials	Difficulty	Safety	Summary
AC vs DC with a Bicolor LED	★★★	★★☆	★☆☆	A bicolor LED connected to a circuit shows the difference between AC and DC power. With DC, the LED glows red or green depending on polarity, while with AC it alternates between colors at 60 Hz. Swinging the LED in a circle makes the rapid switching visible as a multicolored light ring.
Burning Steel Wool with a 9 Volt Battery	★☆☆	★☆☆	★★☆	In this experiment, fine-grade steel wool is ignited using a 9-volt battery. When the steel fibers complete the circuit, they heat up and react with oxygen in the air, producing glowing sparks and forming iron oxide. This demonstrates that metals, like iron, can burn under the right conditions.
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.
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.
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).
Electromagnetic Shielding with a Faraday Cage	★★☆	★☆☆	★☆☆	An AM/FM radio is placed inside a Faraday cage to demonstrate how the cage blocks electromagnetic waves, preventing the radio from receiving signals.
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.
Electrostatic Deflection of a Water Stream	★☆☆	★☆☆	★☆☆	A thin stream of water falling from a cup can be deflected by bringing a charged rod near it. The demonstration shows how the polar nature of water molecules causes them to be attracted to charged objects.
Electrostatic Deflection of Polar vs Nonpolar Liquids	★★☆	★★☆	★★☆	Charged rods can bend a falling stream of polar liquid, such as water, but have no effect on a stream of nonpolar liquid, such as cyclohexane. This demonstrates molecular polarity and explains why polar solvents dissolve ionic compounds.
Energy Stick Human Circuit	★★★	★★☆	★☆☆	The Energy Stick is a safe handheld circuit tester that lights up and buzzes when you complete a circuit by touching its electrodes. It demonstrates conductivity in people and materials, helping students explore conductors, insulators, and the idea of closed circuits.
Franklin’s Bells	★★★	★★☆	★★☆	A small conductive ball swings back and forth between two metal plates, alternately charging and discharging as it contacts each plate.
Franklin’s Bells With Van de Graaff Generator	★★★	★★☆	★★★	A small conductive ball swings back and forth between two metal plates, alternately charging and discharging as it contacts each plate.
Glowing Pickle	★★★	★★★	★★★	When an electric current passes through a pickle, ions in the salty brine conduct electricity, exciting sodium atoms that emit a bright yellow glow. This demonstrates ionic conduction, atomic emission spectra, and electrolysis.
Home Made Electroscope	★☆☆	★★☆	★☆☆	An electroscope is a simple device that detects electrical charge. By using common household materials such as a jar, paperclip, cardboard, and aluminum foil, you can build a working electroscope that demonstrates how charges move and repel each other.
Homemade Electrophorus	★☆☆	★★☆	★★☆	A simple electrophorus device made from a foam plate, aluminum pie plate, and other common materials demonstrates static electricity, voltage, positive and negative charges, resistance, and electron transfer.
Kettle Power	★☆☆	★☆☆	★★☆	Two electric kettles of different power ratings (e.g., 1 kW and 3 kW) are compared to show how electrical power relates to the rate of energy transfer. The demonstration illustrates that the higher-power kettle boils water faster and reinforces the relationship P = IV.
LED Photocell	★★☆	★☆☆	★★☆	An LED connected to a voltmeter generates a measurable voltage when illuminated by certain colors of light. White and green light produce a reading, but red light does not, showing that photon energy depends on frequency rather than brightness - evidence of light behaving as particles.
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.
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.
Ohm's Law	★★☆	★☆☆	★★☆	This demonstration uses a simple resistor circuit to verify the relationship ( V = IR ).
Rollback Can	★☆☆	★☆☆	★☆☆	A weighted rubber band is suspended inside a can. Rolling the can forward twists the band and stores elastic potential energy; when the can stops, the band unwinds and drives the can to roll back.
Rolling a Soda Can With Static Electricity	★☆☆	★☆☆	★☆☆	A balloon rubbed on hair or fabric becomes charged with static electricity. When brought near an aluminium can lying on its side, the can rolls toward the balloon without being touched, demonstrating electrostatic attraction and the movement of charges in conductors.
Rope Loop Electric Circuit	★☆☆	★☆☆	★☆☆	A rope loop passed around a circle of students models how electric circuits work. The teacher moving the rope represents the battery, while a student gripping the rope models a resistor or bulb. This activity helps students visualize current, energy transfer, and resistance in circuits.
Series and Parallel Circuits	★★☆	★☆☆	★☆☆	This investigation compares the brightness of bulbs when connected in series versus parallel. Students measure current and potential difference in each case to relate electrical quantities to observed brightness.
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.
Static Electricity with Balloons	★☆☆	★☆☆	★☆☆	Balloons are charged by rubbing them on hair, causing them to attract or repel each other.
Tesla Coil Wireless Lighting	★★★	★★★	★★★	A Tesla coil is used to light fluorescent tubes or neon lamps without any electrical connection, showing how high frequency alternating currents can transfer energy wirelessly.
Van de Graaff Pie Tins	★★☆	★★☆	★★★	A stack of aluminum pie plates placed on top of a Van de Graaff generator’s dome will charge and repel each other. As the generator accumulates charge, the plates lift off one by one, demonstrating that like charges repel.

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