Magnetism Core Questions Flashcards
(25 cards)
What materials are magnetic?
Iron, cobalt, nickel
What is a magnetic field?
A region where magnets, magnetic materials, and also wires carrying currents, experience a force.
What is an induced magnet?
A magnetic material that becomes magnetic when in a magnetic field.
What are the two poles of a magnet called?
North pole and south pole
What happens when two like poles are brought together?
They repel each other
What happens when two opposite poles are brought together?
They attract each other
What is the direction of a magnetic field?
North to south
What are magnetic field lines?
They show the strength and direction of the magnetic field.
Where is the magnetic field of a bar magnet strongest?
At the poles
How do the magnetic field lines show the field is stronger?
Field lines are close together
How do the magnetic field lines show the field is weaker?
Field lines are further apart
Where are the magnetic fields weakest?
Further away from the poles
How do we plot a magnetic field?
Using a plotting compass
Why does the Earth have a magnetic field?
It has a core of molten iron.
What type of magnet does the Earth behave as?
A huge bar magnet
What pole of the Earth’s magnetic field is at the Earth’s North Pole?
South pole of the magnetic field.
What causes the ‘Northern Lights’?
The interaction of solar radiation with the Earth’s magnetic field and atmosphere.
What is the ‘right-hand thumb rule’ used for?
Finding the direction of the magnetic field around a current carrying wire.
What is the magnetic field pattern around a current carrying wire?
Concentric circles centred on the wire.
What is a solenoid?
A coil of wire
How do we describe the magnetic field inside a solenoid?
Strong and uniform
How do we describe the magnetic field outside a solenoid?
Like a bar magnet
What is the key difference between electromagnets and permanent magnets?
Electromagnets can be turned off, permanent magnets cannot.
Give two examples of uses of electromagnets
Any two from: Scrap metal yard crane, Magnetic door locks, Electric bell, Loudspeakers, Headphones, MRI machines, Induction heating for cooking
