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P7 B) Induced Magnets
P7 B) Induced Magnets
Magnets produce magnetic fields and they have 2 poles; a north and a south pole. The north pole of a magnet is positive, and the south pole is negative.
There are two different types of magnets. These are permanent magnets and induced magnets. Permanent magnets produce their own magnetic field all of the time. An example of a permanent magnet is a bar magnet.
Induced magnets are magnetic materials that become magnetic when they are placed inside the magnetic field of another magnet. There is always and attractive force between the permeant magnet and induced magnet.
Both of these outcomes are why there is always an attraction force between a magnetic material and magnet (there is never a repulsion force). Below is a diagram that shows what happens when a magnetic material is placed near a permanent magnet.
There are two different types of magnets. These are permanent magnets and induced magnets. Permanent magnets produce their own magnetic field all of the time. An example of a permanent magnet is a bar magnet.
Induced magnets are magnetic materials that become magnetic when they are placed inside the magnetic field of another magnet. There is always and attractive force between the permeant magnet and induced magnet.
- When the magnetic material is placed next to the north pole of a magnet, the magnet induces the end of the magnetic material that is closest to the magnet to become the south pole of the magnetic material.
- If the magnetic material is placed next to the south pole of a magnet, the magnet induces the end of the magnetic material that is closest to the magnet to become the north pole of the magnetic material.
Both of these outcomes are why there is always an attraction force between a magnetic material and magnet (there is never a repulsion force). Below is a diagram that shows what happens when a magnetic material is placed near a permanent magnet.
When the magnetic field form the permanent magnet is taken away from the induced magnet/ magnetic material, the induced magnet will stop producing a magnetic field. The time taken for the material to lose its magnetism depends on the type of material that the magnetic material is made out of. There are two different types of magnetic materials; these are magnetically soft materials and magnetically hard materials.
Permanent magnets are made out of magnetically hard materials.
- Magnetically soft materials lose their magnetism quite quickly. Iron and nickel iron alloys are magnetically soft materials.
- Magnetically hard materials lose their magnetism quite slowly. Steel is an example of a magnetically hard material.
Permanent magnets are made out of magnetically hard materials.
Paper Clips
Induced magnetism is also why we can make paper clip chains from magnets. When the paperclips are placed inside the magnetic field of the permanent magnet, the paperclips will become magnetic – the paper clips will be attracted to the permanent magnet and each other. This allows us to join many paper clips together. As soon as we remove the permanent magnet, the paper clips lose their magnetism and will no longer be attracted to each other.
Induced magnetism is also why we can make paper clip chains from magnets. When the paperclips are placed inside the magnetic field of the permanent magnet, the paperclips will become magnetic – the paper clips will be attracted to the permanent magnet and each other. This allows us to join many paper clips together. As soon as we remove the permanent magnet, the paper clips lose their magnetism and will no longer be attracted to each other.
Example
We are now going to have a look at a question that will require us to remember the difference
Question
I have 3 blocks. One of these blocks is a permeant magnet, the other is a magnetic material that is not magnetised and the final one is a non-magnetic material. How can determine which block is which if I have a permeant magnet?
We are now going to have a look at a question that will require us to remember the difference
Question
I have 3 blocks. One of these blocks is a permeant magnet, the other is a magnetic material that is not magnetised and the final one is a non-magnetic material. How can determine which block is which if I have a permeant magnet?
In order to answer this question, we need to remember the rules about magnets, magnetic materials and non-magnetic materials. Let’s look at the non-magnetic material first.
A non-magnetic material will never be magnetic. Therefore, when we place the non-magnetic material in the field of a permeant magnet, the non-magnetic material will be the block that experiences no force from the permeant magnet.
We now need to look at the differences between a magnetic material that is not a magnet and a permeant magnet. When a magnetic material that is not a magnet is placed inside the magnetic field of a magnet, the magnetic material will become magnetic and be attracted to the permeant magnet; we will have an induced magnet. This will always happen irrespective of the way that we place the magnetic material in the field of the induced magnet.
If we placed the permeant magnetic in the magnetic field of the other permeant magnet, we will experience a force of attraction from one side and a force of repulsion from the other side. The force of attraction will come about when opposing poles of the magnets are placed next to one another (this can either be north–south, or south–north). The force of repulsion will come about when the two poles from the magnets are the same (this can either be north–north, or south–south).
Here is a summary of what we will observe:
A non-magnetic material will never be magnetic. Therefore, when we place the non-magnetic material in the field of a permeant magnet, the non-magnetic material will be the block that experiences no force from the permeant magnet.
We now need to look at the differences between a magnetic material that is not a magnet and a permeant magnet. When a magnetic material that is not a magnet is placed inside the magnetic field of a magnet, the magnetic material will become magnetic and be attracted to the permeant magnet; we will have an induced magnet. This will always happen irrespective of the way that we place the magnetic material in the field of the induced magnet.
If we placed the permeant magnetic in the magnetic field of the other permeant magnet, we will experience a force of attraction from one side and a force of repulsion from the other side. The force of attraction will come about when opposing poles of the magnets are placed next to one another (this can either be north–south, or south–north). The force of repulsion will come about when the two poles from the magnets are the same (this can either be north–north, or south–south).
Here is a summary of what we will observe:
- The non-magnetic material will never experience a force with the permeant magnet.
- The magnetic material that is not a magnet will be attracted to the magnet in all situations, such as being placed in rightwards and leftwards.
- The permeant magnet will sometimes be attracted due to opposite poles, and other times be repulsed due to same poles.