Lesson on Magnets - FUN delivery
Herein is some information on Magnets from the http://en.wikipedia.org/wiki/Magnet#Characteristics_of_magnets.
Continuing our discussion from yesterday on activity based events to accelearte learning and create a collaborative environment, let us see what the information is, then we will see what I learned from kids some activities that Karen used exceedingly well in her session with technical trainers.
Magnets
Magnets are materials that produce a magnetic field of their own. Extreme examples of magnets are (1) "hard" or "permanent" magnets (like refrigerator magnets), which remember how they have been magnetized, and (2) "soft" or "impermanent" magnets, which lose their memory of previous magnetizations. "Soft" magnetic materials are often used in electromagnets to enhance (often by factors of hundreds or thousands) the magnetic field of a current-carrying wire that has been wrapped around the magnet; when the current increases, so does the field of the "soft" magnet, which is much larger than the field due to the current. Permanent magnets occur naturally in some rocks, particularly lodestone, but they are now more commonly manufactured. When heated a magnet's magnetism goes down and when cooled a magnet's magnetism goes up.
Materials without a permanent magnetic moment can, in the presence of magnetic fields, be attracted (paramagnetic), or repelled (diamagnetic). Liquid oxygen is paramagnetic; graphite is diamagnetic. Paramagnets tend to intensify the magnetic field in their vicinity, whereas diamagnets tend to weaken the magnetic field in their vicinity. "Soft" magnets, which are strongly attracted to magnetic fields, can be thought of as strongly paramagnetic; superconductors, which are strongly repelled by magnetic fields, can be thought of as strongly diamagnetic
Permanent magnets and dipoles
All magnets appear to have at least one north pole (reckoned positive) and at least one south pole (reckoned negative), and the net pole strength of every magnet is zero. Despite their apparent reality, as suggested by the image at the top of the page, where iron filings concentrate in regions of large magnetic field, poles are not physical objects on or in the magnet. They are, rather, a useful concept for describing magnets. Rather than poles being the fundamental unit, it is the magnetic dipole that is the fundamental unit. A magnetic dipole can be thought of as a combination of a positive and a negative pole that are microscopically close to one another and inseparable. This is not a bad description of the magnetic dipole of an electron in a magnetic material.
The effect of aligning many dipoles and placing them head-to-tail in a line is that there appears a north pole at one end and a south pole at the other, with all the intermediate north and south poles cancelling out. The net effect is a very long dipole that appears to have poles only at its ends. Alternatively, aligning many dipoles and placing them on a sheet producing an object whose magnetic field is like that of a wire carrying current around the perimeter of the sheet. Although theories have been developed involving the possibility of north and south magnetic monopoles, no magnetic monopole has yet been found.
What I learned from the kids
I saw two magnets - basically arrow like play things that my daughter was playing with. I grabbed both of them and tried to match them at the centre. I had forgotten my basic physics. Meena, my niece then remarked that you can't do that because of the north pole and south pole, the positive and negative. My son Maha jumped in to say that the net pole strength of every magnet is zero and you can't do it because of the resistance between the north and south poles. My son Subu then joined in to talk about magnetic fields. I learned so much from this simple activity and it resulted in a productive learning event for the kids.
What was Karen's experience?
The technical trainers in Karen's class used this activity as a warm up, wrap up, as an experiential activity. Learning points such as that when heated a magnet's magnetism goes down and when cooled a magnet's magnetism goes up came from the learners.
Whoever said FUN can't be used in technical training.
Heavy content was deliverd in an engaging manner.
The result participants stayed, enjoyed and learned.
Continuing our discussion from yesterday on activity based events to accelearte learning and create a collaborative environment, let us see what the information is, then we will see what I learned from kids some activities that Karen used exceedingly well in her session with technical trainers.
Magnets
Magnets are materials that produce a magnetic field of their own. Extreme examples of magnets are (1) "hard" or "permanent" magnets (like refrigerator magnets), which remember how they have been magnetized, and (2) "soft" or "impermanent" magnets, which lose their memory of previous magnetizations. "Soft" magnetic materials are often used in electromagnets to enhance (often by factors of hundreds or thousands) the magnetic field of a current-carrying wire that has been wrapped around the magnet; when the current increases, so does the field of the "soft" magnet, which is much larger than the field due to the current. Permanent magnets occur naturally in some rocks, particularly lodestone, but they are now more commonly manufactured. When heated a magnet's magnetism goes down and when cooled a magnet's magnetism goes up.
Materials without a permanent magnetic moment can, in the presence of magnetic fields, be attracted (paramagnetic), or repelled (diamagnetic). Liquid oxygen is paramagnetic; graphite is diamagnetic. Paramagnets tend to intensify the magnetic field in their vicinity, whereas diamagnets tend to weaken the magnetic field in their vicinity. "Soft" magnets, which are strongly attracted to magnetic fields, can be thought of as strongly paramagnetic; superconductors, which are strongly repelled by magnetic fields, can be thought of as strongly diamagnetic
Permanent magnets and dipoles
All magnets appear to have at least one north pole (reckoned positive) and at least one south pole (reckoned negative), and the net pole strength of every magnet is zero. Despite their apparent reality, as suggested by the image at the top of the page, where iron filings concentrate in regions of large magnetic field, poles are not physical objects on or in the magnet. They are, rather, a useful concept for describing magnets. Rather than poles being the fundamental unit, it is the magnetic dipole that is the fundamental unit. A magnetic dipole can be thought of as a combination of a positive and a negative pole that are microscopically close to one another and inseparable. This is not a bad description of the magnetic dipole of an electron in a magnetic material.
The effect of aligning many dipoles and placing them head-to-tail in a line is that there appears a north pole at one end and a south pole at the other, with all the intermediate north and south poles cancelling out. The net effect is a very long dipole that appears to have poles only at its ends. Alternatively, aligning many dipoles and placing them on a sheet producing an object whose magnetic field is like that of a wire carrying current around the perimeter of the sheet. Although theories have been developed involving the possibility of north and south magnetic monopoles, no magnetic monopole has yet been found.
What I learned from the kids
I saw two magnets - basically arrow like play things that my daughter was playing with. I grabbed both of them and tried to match them at the centre. I had forgotten my basic physics. Meena, my niece then remarked that you can't do that because of the north pole and south pole, the positive and negative. My son Maha jumped in to say that the net pole strength of every magnet is zero and you can't do it because of the resistance between the north and south poles. My son Subu then joined in to talk about magnetic fields. I learned so much from this simple activity and it resulted in a productive learning event for the kids.
What was Karen's experience?
The technical trainers in Karen's class used this activity as a warm up, wrap up, as an experiential activity. Learning points such as that when heated a magnet's magnetism goes down and when cooled a magnet's magnetism goes up came from the learners.
Whoever said FUN can't be used in technical training.
Heavy content was deliverd in an engaging manner.
The result participants stayed, enjoyed and learned.
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