Magnetism And Electricity Flashcards
North + south
Attract
South + south / north + north
Repel
Which way do magnetic field lines go from
North ——> south
How to make an electromagnet
Electromagnets can be created by wrapping a wire around an iron nail and running current through the wire. The electric field in the wire coil creates a magnetic field around the nail
What is a permanent magnet
A substance made up of small magnetic regions (domains) that all mostly line up and face the same direction
What is an induced magnet
Substances whose domains are not naturally facing the same directions, but when put in a magnetic field of magnetic objects, they are able to line up, making them temporary and induced magnets.
Magnetic metals
Iron
Nickel
Cobalt
What is the magnetic field around a wire
There is a magnetic field around a wire that carries current
When the current flows up the magnetic field goes
Anti-clockwise
When the current goes down the magnetic field line is
Clockwise
What does the strength if the field around a wire depend on
- the magnitude of the wire
- the distance from the wire
What is the strength of the magnetic field measured in
Teslas (T)
What is magnetic flux density
The strength of the magnetic field
Magnetic north is equal to
Geographic south
What does a magnet point to
The magnetic North Pole, aka the south
What is a solenoid
Many parallel loops that make a coil, and solenoids often carry a current to create an electromagnet
How do you make a solenoid electromagnet stronger
- add a magnetic core (eg, iron, cobalt, nickel)
- add more loops to the coil
- send a higher amount if current through the solenoid
When a current goes upwards, you model it using a
Dot
When a current goes downwards, you show it with a
Cross (x)
Explain one difference between permanent magnet and an induced magnetic
Even if a permanent magnet is removed from a magnetic field it won’t loose its magnetism, whereas an induced magnet will not retain its magnetic field
The behaviour of a magnetic compass is evidence that the core of the Earth is magnetic. Explain
why.
The magnet will always point north
Describe how the student could use a compass to investigate the
magnetic field produced around a wire. (3 marks)
-> place compass on cardboard and plot an x to where the compass points
-> move the compass to where the x is and plot the new point where the compass now points
-> repeated all the way around the wire
-> repeat at different distances around the wire
Describe how student A can use a compass to plot a magnetic field pattern.
You may draw a diagram to help you answer this question.
-> place magneti on sheet of paper
->place compass near the end of the magnet
-> makr where compass points to with an x
-> move the compass so the opposite end of it is on the x
-> repeat all the way around the magnet
Describe how student B uses iron filings to show a magnetic field pattern.
You may draw a diagram to help you answer this question.
Place paper cover over magnet
Sprinkle iron filings to show field patterns
Why is using a compass better than using iron filings when drawing field lines
-> you can see direction of field lines
What directions do field lines go in
North to south
