Magnetic Poles
There are two types of magnetic poles; every magnet has this pole and a south pole.
What is a north pole?
Magnets attract objects made of iron, nickel, and this third metal.
What is cobalt?
The area around a magnet where its force can be felt is called this.
What is a magnetic field?
An electromagnet is made by wrapping this around an iron core and running electric current through it.
What is a wire (or coil of wire)?
Junkyard cranes use giant ones of these to lift cars.
What are electromagnets?
Like poles do this to each other, while opposite poles attract.
What is repel?
Two north poles will always do this to each other.
What is repel?
Iron filings sprinkled around a magnet line up to show the shape of these invisible lines.
What are magnetic field lines?
Turning off the electric current causes an electromagnet to lose almost all of this.
What is its magnetism?
Electric doorbells and this classroom item both use electromagnets.
What are speakers (or relays, motors, etc.)?
If you break a bar magnet exactly in half, each half will have this.
What is its own north and south pole?
A magnet will attract a paperclip but not a plastic button because of this property.
What is “the paperclip is made of iron/steel (ferromagnetic material)”?
Magnetic field lines always leave the magnet at this pole and enter at the south pole.
What is the north pole?
To make an electromagnet stronger you can add more of these (loops) of wire.
What are turns or coils?
MRI machines in hospitals use extremely powerful ones of these.
What are magnets (or electromagnets/superconducting magnets)?
Earth’s geographic North Pole is actually closest to this magnetic pole.
What is the magnetic south pole?
When opposite poles are brought together, the magnetic force becomes stronger because the magnets do this.
What is attract?
The magnetic field is strongest where the field lines are this.
What is closest together?
Increasing the electric current or using this type of core makes an electromagnet stronger.
What is iron (or a soft iron core)?
Credit card strips and fridge magnets both use this kind of material.
What is magnetic (or ferromagnetic) material?
The end of a freely hanging magnet that points toward the geographic North Pole is called this.
What is the north-seeking pole (or magnetic north pole)?
If a south pole repels an unknown pole, the unknown pole must be this.
What is south?
Magnetic field lines never do this to each other (they never cross).
What is intersect?
The polarity of an electromagnet can be reversed by doing this to the current.
What is reversing the direction of the current?
Maglev trains float above the track because of this magnetic force between the train and the track.
What is repulsion?