Magnetism And Electromagnetism Flashcards
(31 cards)
The two types of magnetic poles
A north seeking pole
South seeking pole
The poles of a magnet are
Where the magnetic forces are strongest
Opposite polls
Like polls
Attract
repel
That magnetic field is
The region around a magnet to wear a force acts on another magnets or magnetic material
The strength of the magnetic field depends on
The distance from the magnets it’s the strongest at the polls
Permanent magnets produce their own
Magnetic field
Induced magnets become a magnet when
Placed in a magnetic field
They lose their magnetism quickly when removed
The arrows on field lines always
Run from north to south and show the direction of the force that acts on the north pole
Flux density
The density of the field line and it indicates the strength of the field at this point the close together the lines are the higher the density
The higher the flux density
The stronger the field and the greater the force that could be felt by another magnet
Accomplice
Contains a small bar magnet
The needle aligned with the earths are magnetic field and points to magnetic North
This provides evidence that the earths core is magnetic
How to plot the field around a bar magnets using the compass
Moving the new door around the compass and drawing the arrow s
When A current flows in a conducting wire
A magnetic field is produced around the wire
Right hand grip method
Thumb point in direction of the current
The fingers pointed in the direction that the field lines should be drawn
The strength of the magnetic field depends on
The size of the current and the distance from the wire
This affects can be seen by placing a magnetic compass a different point on the wire and turning this powersupply on and off
Solenoid is formed when
A wire is looped into a cylindrical coil
I solenoid cam
Increase the strength of the magnetic field creating a strong uniform field inside the solenoid
To create an electromagnet
Add an iron core inside a solenoid Which increases the field strength even more
The solenoid increases the magnetic field strength because
It concentrates along a piece of wire into a small area
The looped shape means magnetic field lines around the wire ate all in the same direction
The magnetic field around a solenoid Similar to that
Roundabout magnets
To find the North Pole of a solenoid
Right hand grip method your fingers follow the direction of the current
Electromagnet in an electric bell
1.When the switch is pushed the electromagnet is magnetised
2. The electromagnet attracts the armature
3.Hammer strike the gong and breaks the circuit
4. The armature springs back completing the circuits again and remagnerising the electromagnet
5.Cycle repeats for as long as the bottom remains pushed
Diagram page 67
The motor effect is
When a current carrying conductor is placed in a magnetic field and experiences a force
The motor effect his caused by
The field created by the current interacting with the magnetic field
