The following is a sequence of experiments that can accompany a standard lecture on electromagnetic waves. The entire sequence is quite long and you may not want to do it all in one lecture.
1) The voltage variation along the length of a dipole transmitting antenna can be made evident. The intensity variation of a fluorescent light bulb, held near the antenna, shows the voltage to be maximum at the ends and minimum in the middle of the dipole. Read more about Radio Wave Properties
The transmission and detection of radio frequency electromagnetic radiation by use of LC oscillator circuits recreates the discovery by Hertz of a method to generate and detect electromagnetic waves. Read more about Hertz Resonator
When a magnetic field is applied perpendicular to a conductor carrying current, a potential difference is observed between points on opposite sides of the conductor. This happens because the magnetic field deflects the moving electrons (Lorentz force) to the edge of the conductor and the altered charge distribution generates a transverse electric field. Read more about Hall Effect
A thin wafer of Ferromagnetic Garnet reveals its magnetic domain alignment as light and dark serpentine patterns when viewed between crossed Polarizers. These domains can be flipped by an external magnetic field, changing the pattern structure. Read more about Magnetic Bubbles
The magnetization of a ferromagnetic substance occurs in little jumps as the magnetic moments of small bunches of atoms, called domains, align themselves with the external field. We can actually "hear" the switching of these domains by amplifying the currents induced in a coil that surround the ferromagnetic material. Read more about The Barkhausen Effect
A large magnet with a small cylindrical gap allows a stream of liquid nitrogen to pass over and through. Poured liquid oxygen hangs between the poles in the strong field until it boils away.
How It Works
Pour the liquid nitrogen first, slowly over the pole pieces. The result is nothing but vapor condensation and crackling plexiglas; the liquid does not interact with the large magnetic field. Read more about Paramagnetism of Oxygen
Stable levitation of one magnet by another is usually prohibited by Earnshaw's Theorem, but the introduction of diamagnetic material at special locations can stabilize such levitation. The demonstration is a replica of an experiment described by M.D. Simon and A.K. Geim1 and is pictured in the photograph. The illustration is from their paper. Read more about Diamagnetic Levitation