P4.1.1 - Magnets and Magnetic Fields Flashcards
How much does the magnetic North Pole move?
30 miles a year
What happens every 500,000 years?
The magnetic poles flip
How can you explain the movement of magnets?
Magnetic field lines
What do field lines represent?
Magnetic flux
What is the number of field lines passing through an area?
Magnetic flux density or magnetic field strength
How do magnets move?
In the direction that makes the field lines shorten
What does the density of the field lines show you?
The strength if the magnetic field
Why is a steel paper clip attracted to a magnet?
The paper clip is an induced magnet
What is a magnet made up of?
Small magnetic regions
What are these domains like in a permanent magnet?
They all line up
What are these domains like in steel or iron?
They are not lined up but when they are in a magnetic field, they do line up
Why do compasses point north?
The North Pole of a compass is attracted to the magnetic South Pole which is near the geographical North Pole of the Earth
Why are most compasses weighted?
So that they lie horizontally
Why do compasses need to be weighted?
The Earth’s magnetic field is like that of a bar magnet
What is the angle between the field lines and a line horizontal to the surface of the Earth?
The dip
