Magnets Flashcards
Magnetism is a force that can ________ and______
Magnetism is a force that can ATTRACT and REPEL.
Is it a contact or non contact force?
Non Contact
What is the name of the two opposite ends of a magnet?
Poles
The ends are known as North and South what?
Seeking
State the Law of Magnetism
Opposite poles attract, alike poles repel.
Are all metals magnetic?
No
Are all magnets metallic?
Yes
Name 3 magnetic metals
Iron, Cobalt, Nickel
Name 3 non magnetic metals
Aluminium, Magnesium, Titanium, Tin, Zinc, Lead, Copper, Gold, Silver, Platinum
What is an alloy?
a metal that has been combined with 1 or more other elements.
Name a magnetic alloy
Steel
Why is Steel a magnetic alloy
It contains a large amount of iron.
Will materials that aren’t magnetic be attracted or repelled by a magnet?
No
What is described here? An area where magnetic materials experience a force.
Magnetic field
Are magnetic fields visible?
No
This describes a practical to see a magnetic field. Fill in the missing words:
Equipment:
Blue Tack
Iron __________
___ Magnet
1 sheet Blank paper
2 books of similar thickness to the magnet.
Method:
- Place magnet central and in between both books.
- lay the paper on top of the magnet and books and blue tack in place
- sprinkle iron _______ on the paper.
- tap paper to move ______ ________
- repeat 4 &5, observe and record results
Equipment: Blue Tack Iron FILINGS BAR Magnet 1 sheet Blank paper 2 books of similar thickness to the magnet.
Method:
- Place magnet central and in between both books.
- lay the paper on top of the magnet and books and blue tack in place
- sprinkle iron FILINGS on the paper.
- tap paper to move IRON FILINGS
- repeat 4 &5, observe and record results
The following are statements of observations from a practical to observe magnetic fields using iron filings. Fill in the missing words.
Iron filings gather along the _____ lines.
_____ of filings will gather at the poles.
The lines appear to ____ the North & South _____ of the magnet.
Iron filings gather along the FIELD lines.
LOTS of filings will gather at the poles.
The lines appear to JOIN the North & South POLES of the magnet.
When drawing magnetic field diagrams can the field lines cross over?
No
When drawing magnetic field diagrams where do field lines start and end?
Start at the North pole, end at the South pole.
Are magnetic fields flat?
No
Which methods have you been shown to plot magnetic field lines using a a bar magnet?
Using a plotting compass or iron filings
What two observations can you make from the compass plotting practical?
- The needle of the compass lines up with the magnetic field line.
- A compass needle will always point from North to South along the field lines when it is placed in the field of a magnet.
The four principles of magnetic field lines are below, fill in the missing words:
Magnetic field lines ________ cross.
Magnetic field line run ______ to ________.
Magnetic field lines are ___________.
When lines are ________ this shows the magnetic force is ___________.
Magnetic field lines NEVER cross.
Magnetic field line run NORTH to SOUTH.
Magnetic field lines are CONTINUOUS.
When lines are CLOSER this shows the magnetic force is STRONGER.
You can magnetise a ______ rod by rubbing a ________ along it.
You can magnetise a STEEL rod by rubbing a MAGNET along it.
A magnetised steel rod will be able to _______ magnetic objects.
The steel rod will be able to ATTRACT magnetic objects.
Will a magnetised steel rod remain magnetic if it is frequently dropped onto a hard surface?
No
Choose the correct word:
A magnetised steel rod is a Permanent/ Temporary Magnet.
A Bar magnet is a Permanent/ Temporary Magnet.
A magnetised steel rod is a Temporary Magnet.
A Bar magnet is a Permanent Magnet.
What will happen to a magnetised steel rod when it is heated?
Is will loose its magnetism.
All of the atoms in a steel rod can be thought of as tiny magnets, what are they called?
Domains
Why is the net magnetism of a steel rod usually 0?
All of the atoms/ domains are facing in different directions and so their magnetic forces cancel each other out.
What happens to the domains when you rub a steel rod with a magnet?
The domains align and the rod becomes magnetic until the domains loose their alignment.
Describe an electromagnet.
A current is passed through a coiled wire, creating a magnetic field.
Are electromagnets permanent or temporary magnets?
Temporary, their magnetism is controlled by the current.
Give two reason why electromagnets are more useful than permanent magnets.
Their magnetic force can be easily switched on and off, and it’s strength adjusted.
What is the name of the coiled wire in an electromagnet?
Solenoid.
What material is the core inside the wire of an electromagnet?
Metal - usually iron.
Does an iron core in an electromagnet decrease or increase its magnetic field?
Increase
Why is steel not usually used for the core material of electromagnets?
Steel is more difficult to magnetise and retains it’s magnetism longer that Iron when the current is switched off.
Name these Variables from their description:
A. The thing you measure
B. The thing you keep the same, to make it a fair test.
C. The thing you change.
A - Dependent variable
B - Control Variable
C - Independent Variable
The strength of an electromagnet can be increased in 3 ways, describe them.
- Add more turn to the wire coil (solenoid), 2. use an Iron core, 3. Increase the current flowing through the coil.
