P5.1 - Electricity & Magnetism Flashcards
Magnetism describes
the ability of magnets to attract (pull towards) and repel (push away) other magnets without touching them.
Magnets have a
north and south pole
Opposite poles on magnets
attracted to each other
Same poles of magnets (north and north or south and south)
repel to each other
The forces between magnets are caused by
invisible magnetic fields
When the magnetic field of two magnets overlaps it causes
the magnets to push or pull
What are the only pure metals that can be turned in a magnetic (magnetic materials)
iron, cobalt and nickel
Magnetically hard materials such as steel are
magnetic once they have magnetized
When we refer to magnets we mean
permanent magnets that are made of magnetically hard materials
magnetically soft materials like iron are
materials that do not stay magnetized
magnetic materials like iron won’t
repel or attract other iron
magnetic materials are attracted to
magnets
What are the properties of magnetic materials
Magnetic materials can be attracted to by magnet but not repelled.
only 2 magnets can repel each other
non magnetic materials will never attract to magnets
permanent magnets are always magnetic
Permanent magnets are responsible for
inducing temporary poles in magnetic materials causing them to attract
Induced magnets are magnetic materials that
become temporary magnets when in a magnetic field
when moved away from permanent magnet a magnetic material will
stop being a magnet
The pole of a permanent magnet always induces
the opposite pole in an unmagnetized piece of magnetic material to attract
What are the ways in which magnetic materials can be turned into permanent magnets
Hammering (putting a magnetic material in a strong magnetic force and hitting it with a hammer)
Solenoid and direct current (putting magnetic material inside a coil of wire and passing a direct current through a wire for several seconds)
Stroking (stroking the material in the same direction with a permanent magnet)
Magnetics have
magnetic field lines around them
The more concentrated field lines are the
stronger the magnetic effect and force
What is an electromagnet
it is made from a cylindrical coil of wire that has an electric current passing through it
An electromagnet is only magnetic when
there is electrical current flowing through it
when an electrical current is switched off the wire loses
its magnetism
What are the 3 ways to increase the strength of an electromagnet
More coils
Higher electric current
Iron core placed inside solenoid
