Magnetism. Flashcards
Magnets have 2 poles. Name them.
North and south poles.
North and south pole will _____ each other.
North and south pole will attract each other.
Two north poles or two south poles will ______ each other.
Two north poles or two south poles will repel each other.
Magnets attract what kind of materials?
Ferromagnetic materials.
Name 4 ferromagnetic materials.
Iron, nickel, cobalt, and steel.
What happens when ferromagnetic material is placed next to a magnet?
Magnetic poles are induced in it (it turns into a magnet temporarily, so it can attract the magnet next to it).
True or False. Ferromagnetic objects can be hung in a chain from a magnet.
True.
Define magnetic field.
A magnetic field is an area around a magnet where a magnetic force has an effect on magnetic materials.
Where do magnetic fields point from?
North to South.
Magnetic field lines touch each other. True or False.
No, magnetic field lines do not touch each other.
Where is the magnetic field strongest?
The magnetic field is strongest where the lines are the closest together.
What does the Law of Magnetism state?
The Law of Magnetism states that like poles repel and unlike poles attract.
Define magnetic forces.
Magnetic forces are non-contact forces that cause movement.
What can be used to measure the magnetic force of attraction?
A forcemeter can be used to measure the magnetic force of attraction.
What is a compass?
A compass is a tiny magnet. It points towards the South pole, and away from the North pole of a magnet.
What can we use a compass for?
We can use compasses to find out what a magnetic field looks like.
The Earth has a ________ _______. There is a lot of liquid ____ in the Earth’s ______ _____. As it moves around it makes a ______ ______.
The Earth has a magnetic field. There is a lot of liquid iron in the Earth’s outer core. As it moves around it makes a magnetic field.
- What does the Earth’s magnetic field protect us from?
- What would happen if the Earth’s magnetic field did not protect us from these things?
- Name an example of this.
The Earth’s magnetic field protects us from the Sun’s cosmic rays which would destroy our atmosphere (this may have happened to Mars).
Define electromagnets.
Electromagnets are magnets which can be switched on and off with electricity.
When the electricity is on, what is the electromagnet doing?
When the electricity is turned on, the electromagnet is on too. It behaves the same as a regular magnet.
When the electricity is off, what is the electromagnet doing?
When the electricity is off, the electromagnet is also off. It is not a magnet anymore, just a piece of iron.
What is an electromagnet made of?
An electromagnet is made of a piece of iron, in a coil of copper wire (the wire carries the electricity).
How can you make an electromagnetic stronger? Name 3 ways.
- Increase the number of turns of the copper coil.
- Increase the voltage of the electric current.
- You can use a different core (it can be a bigger core or different ferromagnetic material).
Define neutral or null point.
A neutral point of a magnet is defined as a point at which the resultant magnetic field is always zero.
