What is a magnet?
What are the ends of the magnet, where the force is greater, called?
What is the name of one naturally occurring magnet? Hint: Shown at the beginning of the chapter.
Explain how poles are attracted or repelled by each other.
Why do farmers give their cows magnets to eat?
What is a magnetic field?
What are lines of force?
What type of magnet is the Earth?
How does a compass use magnets to work?
How would lines of force be shown if you put a magnet under a sheet of paper and iron fillings on top?
Name three materials that are not magnetic.
How do you make a magnet?
What is the difference in the way the atoms are arranged between magnetic and non-magnetic items?
Name two ways to 'demagnetize' a magnet.
Name two materials that can be made into magnets.
What is electromagnetism?
How is an electromagnet created?
Is an electromagnet always magnetic? Explain.
Name three things that require electromagnets to operate.
What is the difference between a motor and and engine?
an object that attracts certain kinds of metals, such as iron
poles
Lodestone (also acceptable: magnetite, iron oxide)
magnetic poles of opposite types (north and south) attract. Poles of the same type repel (north and north or south and south).
Cows do not chew their food, so they often swallow metal objects. Magnets attract these objects so that the cows aren't injured by the objects.
the area around a magnet in which magnetic forces can act
lines that show a magnetic field
a bar magnet
the compass needle is a magnet, as is the Earth. The north pole attracts the north arrow of the compass needle, and it is drawn toward the north pole.
the iron fillings will be attracted to the the magnetic lines of force and arrange themselves accordingly.
wood, copper, plastic, rubber, gold, glass, etc.
take an iron wire and stroke it with a magnet
In magnetic items, the magnetic fields of the atoms line up. In nonmagnetized material, the magnetic fields of atoms do not line up.
heat it or strike it with a hard blow
iron, nickel, cobalt
the relationship between magnetism and electricity
by passing a current through a wire wrapped around an iron core
no, an electromagnet is only magnetic when an electric current is flowing.
speakers, earphones, telephones
motors use magnetic force to change electrical energy into kinetic (mechanical) energy. Engines change chemical energy (fuel) into kinetic energy (mechanical) to operate an automobile.
