Simple Phenomena of Magnetism (Cambridge (CIE) IGCSE Co-ordinated Sciences (Double Award): Physics): Flashcards
Exam code: 0654 & 0973
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Define the term magnet.
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Cards in this collection (26)
Define the term magnet.
A magnet is an object with a north pole and a south pole. It attracts magnetic materials and can attract or repel other magnets.
Define the term magnetic material.
A magnetic material is a material that is attracted to a magnet. It is attracted to both poles and can be magnetised.
Define the term non-magnetic material.
A non-magnetic material is neither attracted nor repelled by a magnet.
Which metals are magnetic?
The magnetic metals are iron, cobalt and nickel. Steel is also magnetic because it is an alloy containing iron.
True or False?
Aluminium is a magnetic material.
False.
Aluminium is not a magnetic material, so it is not attracted to a magnet.
True or False?
Opposite poles attract.
True.
A north pole and a south pole are opposite poles, so they attract each other.
Define the term like poles.
Like poles are poles of the same type, e.g. two north poles. Like poles repel each other.
How can you test whether an object is a magnet?
Bring the object close to a known magnet:
It is a magnet if it is repelled by the known magnet
It is a magnetic material if it is only ever attracted
It is a non-magnetic material if it is neither attracted nor repelled
What is induced magnetism? (Extended Tier Only)
Induced magnetism is when a magnetic material temporarily becomes a magnet while it is inside a magnetic field.
What happens to the ends of a magnetic material when magnetism is induced in it?
One end becomes a north pole and the other a south pole. The end closest to the magnet has the opposite pole to the magnet's nearest pole.
True or False?
Induced magnets keep their magnetism after being removed from the magnetic field.
False.
An induced magnet loses its magnetism quickly when it is removed from the magnetic field.
True or False?
Induced magnetism can cause a magnet to repel a magnetic material. (Extended Tier Only)
False.
Induced magnetism always causes a force of attraction between the magnet and the induced magnet.
Define the term permanent magnet.
A permanent magnet produces its own magnetic field and does not lose its magnetism easily. Permanent magnets are made from materials such as steel.
Why is steel used for permanent magnets but soft iron used in electromagnets?
Steel stays magnetised for a long time, so it is used for permanent magnets. Soft iron loses its magnetism as soon as the cause of the induced magnetism is removed, so it is used in electromagnets and transformers.
An electromagnet is made by winding coils of wire around a ______ core.
An electromagnet is made by winding coils of wire around a soft iron core.
True or False?
An electromagnet can be switched on and off.
True.
The electromagnet is switched on when current flows through the coils and switched off when no current flows.
State three ways to increase the strength of an electromagnet.
The strength of an electromagnet can be increased by:
Increasing the current
Increasing the number of turns of the coil
Adding a soft iron core
True or False?
The strength of a permanent magnet can be changed.
False.
It is not possible to change the strength of a permanent magnet. Only an electromagnet's strength can be changed.
Give two uses of permanent magnets.
Uses of permanent magnets include:
Compasses
Fridge magnets
Toys
School lab experiments
Give two uses of electromagnets.
Uses of electromagnets include:
MRI scanners
Speakers and earphones
Recycling (sorting scrap metal)
Maglev trains
Define the term magnetic field. (Extended Tier Only)
A magnetic field is a region in which a magnetic pole experiences a force.
How is the direction of a magnetic field at a point defined? (Extended Tier Only)
The direction of a magnetic field at a point is the direction of the force on the north pole of a magnet at that point.
What are magnetic field lines? (Extended Tier Only)
Field lines are lines drawn around a magnet to represent its magnetic field. Each line has an arrow showing the direction of the field.
In which direction do magnetic field lines go? (Extended Tier Only)
Magnetic field lines always go from a north pole to a south pole.
True or False?
The magnetic field is strongest at the poles of a bar magnet. (Extended Tier Only)
True.
The magnetic field is strongest at the poles, where the field lines are closest together.
How is the weakening of a bar magnet's field with distance shown by its field lines? (Extended Tier Only)
The magnetic field becomes weaker as the distance from the magnet increases, so the field lines get further apart.
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