Notes from united streaming on magnets
Magnet are used everyday but have been around
Greeks- rocks contained magnetite
China- hung magnet from the string, found it would always point to the north pole. It si
called lodestone
All magnets have a magnetic force, pulling or pushing the north and/or south pole
Opposites attract or pull together
Push apart- repel
Opposites attract
Magnetic forces are the strongest at the magnetic poles
Permanent magnets: horseshoe, bar, disc (all have north and south poles)
Magnetic lines of force act like it has a bar magnetic at the core to create a line of field
Earth is made of iron and nickel
Before they used lodestone to tell direction but now they use compasses.
Approximately 1500 kilometers off of the geographic N and S
Jupiter’s magnetic field is 10 times stronger than the Earth’s. Saturn also has a strong
magnetic field.
Magnetic lines of force (the magnetic field) have broken through the sun’s corona
creating the sun spots
All matter is made of atoms
Nucleus is at the center
protons are nuclear particles that are positive charge
orbiting the nucleus is the electron carrying a negative charge
all spin around creating a magnetic field making each atom a tiny magnet
magnetic domain is when all of the thousands of atoms are arranged int eh same direction
therefore are magnetic
ferromagnetic material is very strong magnetic material
magnets can be made from any ferromagnetic material. Most magnets are man-made
today
temporary magnets is when you rub material together against the same pole of a magnet
permanent magnets can become demagnetize but tend to stay magnetized
heating a magnet can knock a magnet out of alignment
when you break a magnet in half, it becomes 2 smaller magnets
Hans Christian Urstead, a Danish scientist, discovered that when you place a compass
next to a wire that carries electricity, the compass needle was change when the electricity
was on.
Compass needle was only deflected by a magnetic field an electric current produced a
magnetic field
Electricity and magnetism- Urstead found the relationship between the two. Major
discovery- electromagnetism
Electromagnets are a ferromagnets with electric wire around the material. It is strongest
at the center, and at the ends or poles.