magnetism Flashcards
Describe uniform magnetic field pattern
- parallel field
- equally separated and straight
explain why the steel paper clip remains attached to the steel core with the current switched off
- steel is magnetically hard material
- steel becomes permanently magnetized
- still remains magnetized when current switched off so paper clips remain attracted to steal
whats is soft magnetic material
- gets magnetized when an external MF is applied
- but they demagnetized when external MF is removed.
what is hard magnetic material
- gets magnetised easily…
- when external MF is applied and stays magentised permemtantly when external MF is remived
why would iron be used on a fire alarm door?
- Iron is magnetically soft
- Iron loses its magnetism easily
what is meant by the term magnetic field line
- line that shows direction of the magnetic force/field
The current in the wire is 10 A why is the wire thick?
- thin wire would melt
- to reduce resistance
if you get a photo that shows a very curved magnetic field what can you assume?
Field is not uniform and feel direction is constant/same direction
4 terms you must know
- induced magnet
- permanent magnet
- magnetically hard
- magnetically soft
- induced magnet- is a magnetic material only in a magnetic field
- permanent magnet-produces its own magnetic field
- magnetically hard-easily magnetized (stays magnetized)
- magnetically soft-easily magnetized (induced/temporary)
what is a permanent magnet
- a magnet that produces its own MF
- cannot be demagnetised
- made from magnetic material
4 more magnetic material
- iron
- cobalt
- nikel
- steel
how to produce a uniform magnetic field
- two permanent magnets
- poles angled correctly (north facing south)
- magnets correct distance apart (close together but not touching)
construct a diagram of an electromagnet
- insulated wire
- wrapped into core
- wrapped around iron core
