Magnetism
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Introduction:
What is a magnet? Magnets are characterized by having two poles, designated as north pole and south pole. These poles exert a magnetic field around the magnet. A magnetic field is a field of influence which exerts a force on magnets or other charged particles.
Like poles of magnets repel each other, whereas opposite poles attract.
Simple ways to demonstrate the interaction with a magnetic field are with iron fillings and compasses.
Properties of Magnets and Magnetic fields.
How permanent magnets are created.
Magnets are put through a very strong magnetic field. Metals are made up of atoms which have small magnetic segments called moments. Usually, each of these moments are aligned in different directions, leaving the net magnetism effect of a piece of metal to be effectively zero. However, when the piece of metal is put through a strong magnetic field, all of the moments align themselves in the same direction, imbuing the piece of metal with magnetic properties.
What if you want to separate a bar magnet into north and south poles? It is Impossible to separate a north pole and south pole from a magnet. When a magnet is broken it simply becomes two smaller magnets.
Magnetic Field lines Activity:
Split class into groups of 4, pass out magnets and iron fillings to each group.
Ask students to attempt to make the two different patterns shown by two magnets with opposite poles next to each other(left) and two poles repelling each other(right).
What is a magnet? Magnets are characterized by having two poles, designated as north pole and south pole. These poles exert a magnetic field around the magnet. A magnetic field is a field of influence which exerts a force on magnets or other charged particles.
Like poles of magnets repel each other, whereas opposite poles attract.
Simple ways to demonstrate the interaction with a magnetic field are with iron fillings and compasses.
Properties of Magnets and Magnetic fields.
How permanent magnets are created.
Magnets are put through a very strong magnetic field. Metals are made up of atoms which have small magnetic segments called moments. Usually, each of these moments are aligned in different directions, leaving the net magnetism effect of a piece of metal to be effectively zero. However, when the piece of metal is put through a strong magnetic field, all of the moments align themselves in the same direction, imbuing the piece of metal with magnetic properties.
What if you want to separate a bar magnet into north and south poles? It is Impossible to separate a north pole and south pole from a magnet. When a magnet is broken it simply becomes two smaller magnets.
Magnetic Field lines Activity:
Split class into groups of 4, pass out magnets and iron fillings to each group.
Ask students to attempt to make the two different patterns shown by two magnets with opposite poles next to each other(left) and two poles repelling each other(right).
Switch back to magnetic field diagrams to show the similarities between the magnetic field vectors and the iron fillings that they have in their hands.
Magnetic Levitation:
The principle of magnetic levitation is simple. The force of the magnetic attraction or repelling force is equal to the weight of whatever is being levitated.
To demonstrate, use the magnetic donuts experiment. Show how the magnetic pieces repel and levitate and explain that it is because the magnetic force is equal to the weight of the magnet.
Magnetic Levitation:
The principle of magnetic levitation is simple. The force of the magnetic attraction or repelling force is equal to the weight of whatever is being levitated.
To demonstrate, use the magnetic donuts experiment. Show how the magnetic pieces repel and levitate and explain that it is because the magnetic force is equal to the weight of the magnet.
Magnetic Train
The donut experiment shows the concept of magnetic levitation and the dowel in the middle serves to keep the magnets from flipping over. An example that is more impressive is the levitating train which operates on the exact same principles.What stops the train from flipping are the side rails that hold the train in place. The train stays levitated by the repelling force of the magnets under the car and on the track.
The donut experiment shows the concept of magnetic levitation and the dowel in the middle serves to keep the magnets from flipping over. An example that is more impressive is the levitating train which operates on the exact same principles.What stops the train from flipping are the side rails that hold the train in place. The train stays levitated by the repelling force of the magnets under the car and on the track.