Magnetism and Electromagnetism Flashcards
What are the 2 poles on a magnet?
North and South
Where on a magnet are the magnetic forces the strongest?
The poles
What do two like poles do ?
Repel each other
What do two opposite poles ?
Attract each other
How do non-contact forces work with magnets?
When two forces are brought together the exert a force on each other but they aren’t touching.
The attraction and repulsion between 2 magnetic poles.
What is a Permanent Magnet?
A magnet which produces it’s own magnetic field
What is an Induced Magnet?
It is a material which becomes a magnet when it is placed in a magnetic field.
What does Induced magnetism always cause ?
A force of attraction but when it’s removed from the magnetic field, the induced magnet loses all/ most of it’s magnetism quickly.
What is a magnetic field ?
It is the region where a force acts on another magnet or on a magnetic material
(Iron, steel, cobalt and nickel)
What does the strength of the magnetic field depend on?
The distance from the magnet
How does the direction of the magnetic field and force relate?
The direction of the magnetic field (at any point) is given by the direction of force that would act on another north pole placed at the point
Where is the direction of a magnetic field line ?
It’s from the North (seeking ) pole to the South (seeking) pole.
What does a magnetic compass have inside?
A small bar magnet because the earth has a magnetic field and the compass points in the direction of the earth’s magnetic field.
What is a Electromagnet?
A solenoid with a Iron core
What happens when a current flow through a wire ?
A magnetic field is produced around the wire.
What does the strength of the magnetic field of a wire depend on?
The strength of the current through the wire
The distance from the wire.
How do you increase the strength of the magnetic field of a wire?
By coiling the wire to make a Solenoid due to the small magnetic fields caused by each turn of the current add together to make one big magnetic field
What is the magnetic field of Solenoid like?
Strong and Uniform
How do you increase the strength of a Solenoid?
You add an iron core into the Solenoid
(has a similar shape to a bar magnet)
What is the Motor Effect?
When a conductor carrying a current is placed in a magnetic field, the magnet producing the field and the conductor exert a force onto each other
What is magnetic flux density measured in?
Tesla (T)
What is current measured in?
Amperes (A)
What is length measured in ?
Meters (M)
What is the basis of an electric motor ?
When a coil of wire carrying a current tends to rotate ( best at 90 degrees)
