Nail Induction

1. Nail Induction Supplies: • Nails (large and small) • Paper clips • Strong magnet • Magnetic Magic • Ball bearings Procedure: • Attach nail to magnet. • Dip nail into nails/paper clips. What’s Happening: • The magnetic field forces the poles inside the nail to align, inducing a magnetic field through it. In essence, turning the nail into a magnet. Similarly, the base of the Magnetic Magic is magnetic and causes the shards of metal to act as magnets too. Notes: • See how many things you can string together. • Is this related to the strength of the magnet? • Try to make designs out of the little nails or paper clips.

2. Levitation by Pringles Can Supplies: • Pringles cans with lids • Nail • Paper clip • Magnet Procedure: • Poke nail through can an inch from the bottom, perpendicular from the view through the window. • Cut string to the length of the can. • Tie one end around the nail in the can and the other end around the paper clip. • Put lid on can and then magnet on top. • Pull the paper clip up until the magnet starts attracting it. What’s Happening: • The force of the magnet is working against the force of gravity to hold the paper clip up. Notes: • By varying the length of the string, you can see the distance dependence of the magnetic force. • The farther away, the less force.

3. Levitation by Pringles Can & Maglev Trains Supplies: • Levitation by Pringles can • Pringles cans with lids • Nails • Paper clip • Magnet • Maglev trains • Small colored ring magnets • Pencils Procedure: • Levitation by Pringles can • Poke nail through can an inch from the bottom, perpendicular from the view through the window. • Cut string to the length of the can. • Tie one end around the nail in the can and the other end around the paper clip. • Put lid on can and then magnet on top. • Pull the paper clip up until the magnet starts attracting it. • Maglev trains • Take stand or pencil. • Place the rings on the stand/pencil and see if they attract or repel. • Place the top ring the opposite way and observe what happens. • Experiment with moving the rings up and down the stand/pencil. What’s Happening: • Levitation by Pringles can • The force of the magnet is working against the force of gravity to hold the paper clip up. • Maglev trains • Maglev trains work by putting repelling magnets near each other. The train floats on top of the track, so friction is greatly reduced. Notes: • Levitation by Pringles can • By varying the length of the string, you can see the distance dependence of the magnetic force. • The farther away, the less force. • Maglev trains • All magnets have two poles, north and south. • When two poles are the same, the magnets repel. • When two poles are opposite, they attract.

4. Eddy Currents & Damping Forces • Procedure: • Eddy Currents • Turn the Eddy Tube back and forth upside down. • Roll the ball bearing down the V-tube. • Roll the ball magnet down the V-tube. • Damping Forces • Run magnet back and forth over the various bars. • Make the fork-swing sway on the swing set. • Repeat with other swings. Supplies: • Eddy Currents • Eddy Tubes • Ball bearing • Ball magnet • Aluminum V-shaped tube • Damping Forces • Copper bar • Magnets • Aluminum sheet • Plastic bar • Magnetic swing set What’s Happening: • Eddy Currents • When the magnets are going through the tubes, the changing magnetic field induces a current, generating a magnetic field. The two fields interact and slow the magnet. • Damping Forces • See above. Notes: • Eddy Currents • Orient the ball magnet with poles pointing into bar and parallel with bar, observe differences. • Remove one bar in the Cu tube (one is magnetic the other is not), and compare how they move. • Damping Forces • Moving magnet faster causes more resistance. • Use swings without the magnet to show natural movement.

5. Magnetic Games Supplies: • Maze • Cow magnets • Magnetic Maze • Steal marble/ball bearing • Play with magnets • Magnetic view finder • Magnetic field observation box • Magnetic film • Iron fillings • Compass • Magnetic Magic • Bar magnets • Bar magnets Procedure: • Maze • Use magnet on top or bottom to guide ball through maze. • Play with magnets • Give kids magnets, view finders, and observation box. • Explore properties with magnetic film, iron fillings, and etc. • Bar magnets • Learn about poles and attractive/repulsive force. What’s Happening: • Maze • Magnetic force pulls the ball through the maze. • Play with magnets & Bar magnets • Pertains to the poles of the magnets and the lines of the magnetic field. Notes: • Magnetic force can go through glass, a table, or anything else that is not too thick. • Magnets always have a north and south pole. • Most refrigerator magnets are composed of many bar magnets with alternating poles.

6. Motional EMF Loops & EMF Flashlights Procedure: • Motional EMF Loops • Put battery in motor. • Put magnet on top of motor. • Put coiled wire in leads. • Push gently to make it spin. • Connect coil to ammeter. • Move magnet through coil. • EMF Flashlights • Put magnet in flashlight. • Shake. Supplies: • Motional EMF Loops • Ammeter • Copper wire (coiled) • C battery • Electric motor • Magnets • EMF Flashlights • EMF flashlights • Magnets What’s Happening: • Motional EMF Loops • When current is flowing through the loop, it creates a magnetic field, aligning with the magnet in the base. It spins the wire out of the stripped part on the sides and disrupts the current, eliminating the field. The wire spins due to momentum and swings back into allowing the current, and the process repeats. • A changing magnetic field in a loop of wire induces a current. As the magnetic field changes (by moving magnet back and forth), the current oscillates one way and the other at different strengths. • EMF Flashlights • See above. As the magnet moves through the coil of wire, it changes the field strength, inducing a current. That current is stored on a capacitor in the flashlight which is used to power the flashlight when on. • Notes: • Motional EMF Loops • Half of the wire leads have the insulation stripped away on the motor. • EMF Flashlights • Hold in the sides of the homemade flashlights, otherwise they may become dislodged.