Check for the presence of natural magnetism and transfer the magnetic properties from a natural magnet to a small steel object.
Magnet, metal paperclips
Place a magnet near some metal clips: they will be attracted by the magnet. They do so because they are made of steel, a material that contains a large percentage of iron. Most of the clips remain attached only at the ends, which are called magnet poles. This is because the magnet’s force of attraction is strongest at the poles. The clips can in turn become magnetic. A paper clip can also attract other clips.
Changing an electrical signal into an audible sound
Some packing tape, a plastic cup or container, a strong magnet, a bottle cap or other round object slightly wider than the magnet, copper wire, gator clips, auxiliary cable.
1. Coil the copper wire around the magnet 6-7 times starting from the middle leaving 60 cm of uncoiled wire on either side of the magnet. Remove the magnet and tape the coiled wire to the bottom of your upside down plastic container.
2. Use a bottlecap or other round object to make another, larger coil and leave some uncoiled wire at the ends as before.
3. Place the magnet within both coils. Don’t worry if it does not touch every point on the wire.
4. Wrap one end of the wire around the tip of the jack of an “auxiliary” cable and the other around the bottom and secure each with a gator clip. Plug the auxiliary cable into your music source, like your iPod, and listen.
Apply the knowledge of electromagnetism to wireless telegraphy.
Gas lighter, LED, Battery holder, Coherer, Aluminum shavings.
1.After making the circuit, insert the aluminum shavings into the upper part of the coherer until the screws are covered.
2. Adjust the distance of the screws so that the LED lights up and move them away slightly, checking that the LED turns off.
3. Turn on the gas lighter 5-10 cm away from the coherer; the LED will light up and remain lit even when the spark disappears.
4. Beat your hand firmly on the table; the coherer will return to the initial state and the LED will turn off.
5. Connect one end of a 40-50 cm long electrical wire to the external metal part of the gas lighter and try to operate it at a greater distance … you will have inserted an antenna!