Magnetism and electromagnetism Flashcards
What are induced magnets
When magnetic materials become magnetic when they are placed in a magnetic field
THEY LOSE THIS MAGNETISM WHEN REMOVED FROM MAGNETIC FIELD
THEY ALWAYS ATRAAACCCCCTTTT
Name all magnetic elements
Iron, Nickel, Cobalt
Where is the magnetic south pole on earth
Geographical north
This is why the north needle points north
What produces the magnetic feild on earth
Liquid iron core
What is Flemming’s left hand rule and what do the fingers represent
Because when a electric current is placed inside a magnetic field
Thumb is the force acting on the wire
Index finger is magnetic feild
Middle finger is current
How to plot field lines
Iron filings, plotting compass
What happens when current is passed through a wire
When current passes through a wire it produces perpendicular and concentric rings of magnetism
What is a solenoid
A coiled up wire with current passing through it that produces a magnetic field similar to a bar magnet
What is an electromagnet
A solenoid that has been insulated usually with an iron core (this increases it’s strength)
Motor effect
If a loop of wire is placed inside a magnetic field it will rotate
A wire carrying a current perependicular to a magnetic feild will feel a force
How does an electric motor work
The loop of wire is placed inside magnetic feild and it rotates
The split-ring commutator changes the direction of the DC current every half turn to ensure the wire keeps spinning.
What is the generator effect
As a coil of wire spins in a magnetic field current is produced or magnet moves around a wire
When is AC produced from a generator
Whenever a commutator is not used
How to increase current produced from generator effect
Stronger magnetic feild
More coils
For transformers if there is more coils on the secondary coil the voltage
Increases
