Magnetic Duck

Make two ducks from paper doubled over and glued and push a magnetised pin into each one. Place the ducks on cork disks in a dish of water.After moving around they line up with their beaks or tail tips together in a north-south direction.

 
The ducks approach each other along the magnetic field lines. Their movement is caused by different forces: the attraction of unlike magnetic poles, the repelling effect of like poles, and the earth’s magnetism. Set the magnets so that two poles which will be attracted are placed in the beaks.

Dip to The Pole

Magnetise two steel pins so that their points attract each other strongly. 

Push them into the ends of a piece of foam plastic about as thick as a pencil and balance this by means of a sewing needle over two tumblers (by shifting the pins and pulling off pieces of plastic), if you allow this compass to swing in a north-south direction, it will come to rest with the end facing north sloping downwards.

The compass needle comes to rest parallel to the magnetic field lines, which span the earth from pole to pole. This deviation (dip) from the horizontal is 670 in London, 720 in New York. 600 in Los Angeles and at the magnetic poles of the earth 900.

Compass Needle

Stroke a sewing needle with a magnet until it is magnetised and push it through a cork disk. Put the needle into a transparent plastic lid containing water and it turns in a north- south direction. Stick a paper compass card under the lid.

The needle points towards the magnetic North pole of the earth. This lies in North Canada and is not to be confused with the geographical North Pole, round which our earth rotates. 

The deviation (declination) of the magnetic needle from the true north is 80 in London and 150 in New York (in a westerly direction) and l0 in Chicago and 150 in LosAngeles, (in an easterly direction).

Magnetism Field lines

Lay a sheet of drawing paper over a magnet - of course you already know how to make a magnet - and scatter iron filings on it. Tap the paper lightly, and a pattern forms.

The filings form into curved lines and show the direction of the magnetic force. You can make the pattern permanent. 

Dip the paper into melted candle wax and let it cool. Scatter the iron filings on it. If you hold a hot iron over the paper after the formation of the magnetic lines, the field lines, the pattern will be fixed.

Electric Light

In many homes there is a voltage tester, generally in the form of a screwdriver. In its handle there is, amongst other things, a small neon tube, which you can easily remove. Hold one metal end firmly and rub the other on a piece of hard foam plastic which may be used for insulation. The lamp begins to glow as it is rubbed to and fro, and you can see this particularly clearly in the dark.

Since the plastic is soft, its layers are rubbed against one another by the movement of the lamp and become strongly charged with electricity. The electrons collect on the surface, flow through the core of the tiny lamp, which begins to glow and into the body.

The ancient Greeks had already discovered that amber attracted other substances when it was rubbed. They called the petrified resin ‘electron’. The power, which has caused such fundamental changes in the world since then therefore, gets its name - electricity.

Hostile Balloons

Blow two balloons right up and join them with string. Rub both on a woollen pullover and let them hang downwards from the string. They are not attracted, as you might expect, but float away from each other.

Both balloons have become negatively charged on rubbing because they have taken electrons from the pullover, which has now gained a positive charge. 

Negative and positive charges attract each other, so the balloons will stick to the pullover. Similar charges, however, repel one another, so the balloons try hard to get away from each other.

Clinging Balloons

Blow up some balloons, tie them up and rub them for a short time on a woollen pullover. If you put them on the ceiling, they will remain there for hours.

The balloons become electrically charged when they are rubbed, that is, they remove minute, negatively charged particles, and called electrons, from the pullover. 

Because electrically charged bodies attract those,which are uncharged,the balloons cling to the ceiling until the charges gradually become equal. This generally takes hours in a dry atmosphere because the electrons only flow slowly into the ceiling, which is a poor conductor.