magpage

10) Magnetism

a) General Magnets

Very Large Radar Magnets

Horseshoe shaped +/- 3000 Gauss magnets.

Round Bar Magnet Set

Can be used with the spindle to demonstrate north/south polarity and attraction.

Rectangular Bar Magnet Set
Assorted Compasses

Can be used on overhead projector to show B-Field

Neodymium Magnets

Extremely strong yet small sized magnets.

Spindle Stand
Electromagnet

Shows the property of an electromagnet where two students can try to pull it apart

Liquid Magnetic Field Model for Overhead Projector

Shows the same thing as sprinkling iron fillings around a bar magnet.
It is just contained so it is cleaner.

B Field around a Wire

Iron filling sprinkled around a current carrying wire to show the magnetic field.
This is set up on the overhead projector for students to see.

Magnetic Domain Model with Pivoting Magnets for Overhead Projector

Small dipole magnets are mounted on spindles to show magnetic domains

3-D Magnetic Field Model

Clearly and cleanly shows a magnetic field in 3-D using a magnet inserted in a liquid
/iron fillings chamber.
This is not very large.

Toroid Model

A long solenoid made from a garden hose and wire that can be wrapped into a toroid.

Magnetic Dip Needle Demonstration

Shows dip angle, but can also be used as a very large compass.

Iron fillings

b) Magnetic Forces

Force on Wire Stand

Shows the force on a current carrying wire in a magnetic field.
The wire is mounted on a swinging pivot so it can eject itself from the magnet.
The wire can also be manually moved through the field to produce current on a
Ballistic Galvanometer.

Two Wire Repulsion Stand

Shows the repulsion between two current carrying wires.
A laser beam bounces off a mirror on the stand, which makes the effect obvious

Cathode Ray Tube (Crooke's tube)

Shows the effect of a b-field on an electron beam. c) Lenz's Law and Eddy Currents

Current Direction Indicator with LED Lights

Shows the direction of the voltage/current flow created when a magnet is pushed into a coil.

Copper Tube for Neodymium Magnet

Dramatically shows eddy currents when an aluminum slug and a magnet are dropped down
a copper tube. The aluminum slug falls freely while the magnet produces eddy currents and
Therefore the forces dramatically slow its fall.

Solid and Slit Copper Plate Pendulum (Eddy Current Brake)

Shows how eddy currents build to large values in a solid copper plate and don't in a plate
full of slits. The tow plates are swung like a pendulum through the poles of a magnet.
The solid plate stops immediately between the poles while the slit plate is not effected.

Floating Eddy Current Disk

Eddy currents float a 10 inch disk about 1 inch above a power supply

Jumping Rings

Eddy currents cause aluminum rings to jump off an iron core solenoid.

Hall Probe (Hall Effect)

Detects and measures B-field perpendicular to the probe using hall effect

Hall Generator

Set of rotating disks that produce DC current.
This one is tricky to explain how it works and has to be seen to fully explain it.

Y-Ba-Cu-O High TC Superconductor Kit