Chapter 12: Magnetism Flashcards
Magnets, Magentic materials, Methods of magnetisation and demagnetisation, Magnetic Field, Temporary and Permanent Magnets, Right hand grip rule
Why are magnets magnetic?
The magnetic domains within the magnet are aligned along the same direction
What are some properties of magnets?
Attratcs magnetic materials
Has two poles where the resulant attractive force appears to be concentrated
When freely suspended, the North pole of the magnet always faces North
Between two magnets, their like poles repel eac other, while their unlike poles attract each other
What are some properties of magnetic materials?
Attracted to magnets
May become magnetised
Almost all magnetic materials are metals
What are some common examples of metals that are not magnetic materials?
Aluminium, Copper, Brass, Gold, Silver, Lead
What is magnetic induction?
The process where an object made out of a magnetic matieral becomes a magnet when it is near or in contact with a magnet
What are some methods of magnetising a magnetic material?
Single and Double Stroking
Electrical Method (Using DC Current): Placing the object in a solenoid carrying direct current
What are some methods of demagnetising a magnetical material?
Hammering and Heating
Electrical Method (Using AC Current): Placing the object in a solenoid carrying alternating current
What is a magnetic field?
The region where magnets are able to exert a force on magnetic materials
What are some ways the magnetic field pattern of a magnet can be found / illustrated?
Sprinkling iron filings around the magnet
Plotting the magnetic field using a compass
In which direction do magnetic field lines point?
From the North pole to the South pole
How are stronger magnetic fields represented?
The magnetic field lines are drawn closer together without intersecting
What is the difference between temporary and permanent magnets’ ability to retain their magnetism?
Temporary magnets can only retain their magnetism when in the presence of either an electrical current or in a permenant magnetic field
Permenant magnets can retain their magnetism without the presence of an electrical current or permenant magnetic field
What is the difference between temporary and permanent magnet’s ability to be magnetised?
Temporary magnets are easily magnetised and demagnetised, while permenant magnets are not easily magnetised and demagnetised
What are some uses for temporary and permanent magnets?
Temporary: Electromagnets
Permenant: Compass, Motors, Ammeters
What is the right hand grip rule used for?
Determining the poles of a magnet in a solenoid
