Magnetism and Electromagnetism Flashcards
Where on a magnet are the magnetic forces strongest?
At the poles
What happens when two opposite poles are brought together?
They attract
What happens when two like poles are brought together?
They repel
Is magnetism a contact or non-contact force?
Non-contact
What is a permanent magnet?
A material that produces its own magnetic field
What is a temporary magnet?
A material that is only magnetic when placed in a magnetic field, will lose its magnetism when removed
When does a wire generate a magnetic current?
When current is flowing through it
For the right hand rule, what does the thumb represent?
The direction of the current
For the right hand rule, what do the fingers represent?
The direction of the magnetic field
What does the strength of the magnetic field around a wire depend on?
The size of the current, distance from the wire
What is a solenoid?
A coil of wire
What is an electromagnet?
A coil of wire with an iron core
How can an electromagnet be made stronger?
More coils, increased current, soft iron core
What is the motor effect?
When a conductor carrying a current is placed in a magnetic field, the conductor and magnet exert a force on each other
For Fleming’s left hand rule, what does the thumb represent?
The direction of movement/motion
For Fleming’s left hand rule, what does the first finger represent?
The direction of the magnetic field
For Fleming’s left hand rule, what does the second finger represent?
The direction of the current
What equation links current, length, force and magnetic flux?
Force = Magnetic flux x Current x Length
What are the units for magnetic flux?
Tesla, T
What are the units for current?
Amps, A
What are the units for force?
Newtons, N
What is a compass?
A small, suspended bar magnet which points North
What is a compass used for?
Navigation using the Earth’s magnetic field
Why does the Earth have a magnetic field?
The liquid iron and nickel outer core moves around the solid iron and nickel core
