Lesson 1 - Magnetic Field

Introduction to magnetic fields

Magnets

• - One of the main properties of magnets are that they exert forces on each other at a close distance.
• - All magnets are polarised: this means they have two distinct ends (a north and south pole).
• - A simple rule is that opposites attracts eachother.
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Magnetic forces

• - Magnetic force is a force that is present at all times in a region of space that surrounds all magnets.
• - The force is weakened by increase in distance between objects.
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Representing the magnetic field

• When it comes to physics, a qualitive explanation is not sufficient to grasp the extent of the concept.
• ie. you need a quantitive answer involving mathematical reasoning.
• - The magnetic field can be represented by a vector field as the magnitude of magnetic forces differ from region to region.
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Magnitude and direction of magnetic field

• - The size/magnitude of a magnetic field at any point in the field is depicted by magnetic field strength, (B). Where the units are called Teslas (T).
• - The Direction of a magnetic field is the direction in which a pole of a magnet would face in a certain region.
• - The general direction is north to south as a north pole would face this direction.

Bar Magnets

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• Caption: A bar magnet
• - On a bar magnet, the magnetic field is depicted in closed loops that start from north to south poles.
• - The force is more immense at the ends as the vectors are closer to eachother

Uniform Magnetic Field

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• Caption: Uniform Magnetic field
• Put simply is a field in which the magnetic forces remain constant and do not change in the region, as shown by the two parallel magnets.