MAGNETIC POLES The magnetic force surrounding a magnet is not uniform. There exists a great concentration of force at each end of the magnet and a very weak force at the center. Proof of this fact can be obtained by dipping a magnet into iron filings (fig. 1-8). It is found that many filings will [...]
Magnetic Reversals - Scientists tell us that our magnetic poles have reversed in the past, and that they will again. The last one occurred 780,000 years ago. The average time period between reversals is 450,000 years, but there isn’t really any pattern, it is random. We are overdue by average only. Scientists don’t really know [...]
Measuring Magnetic Fields After reading this section you will be able to do the following: Determine how the direction and intensity of magnetic fields can be found. Describe how a field indicator and a Hall-effect meter work. Since it is impractical to measure the actual field strength within the material, all the devices measure the [...]
Circular Magnetic Fields: Distribution and Intensity After reading this section you will be able to do the following: Explain the distribution and intensity of magnetic fields around conductors Explain what the skin effect is As discussed previously, when current is passed through a solid conductor, a magnetic field forms in and around the conductor. The [...]
Longitudinal Magnetic Fields Longitudinal magnetic fields refer to magnetic fields that are oriented parallel to the direction of propagation of a wave or particle. These fields play a crucial role in various scientific and technological applications, including particle accelerators, plasma physics, astrophysics, and magnetic resonance imaging (MRI). In the context of particle accelerators, longitudinal magnetic [...]
Electricity and Magnetism After reading this section you will be able to do the following: Discuss what happens to a compass when a wire with electrical current is near. Describe the relationship between electricity and magnetism. Why does the compass respond when it is near an electrical wire with current flowing through it? We can [...]
Electromagnetic Fields After reading this section you will be able to do the following: Describe the magnetic fields that surround a current carrying conductor. Iron filings scattered in the vacinity of a current carrying wire will reveal a magnetic field perpendicular to the current flow. Magnetic field lines directed out of the page towards the [...]
Magnetic Field Characteristics After reading this section you will be able to do the following: Describe magnetic fields in different shaped magnets. Understand the important properties possessed by magnetic lines of force. Magnetic Field In and Around a Bar Magnet As discussed previously, a magnetic field is a change in energy within a volume of [...]
Creation of Magnetic Fields After reading this section you will be able to do the following: Define a magnetic field and explain how it is created. Magnetic Field Creation A magnetic field describes a volume of space where there is a change in energy. As Ampere suggested, a magnetic field is produced whenever an electrical [...]
Magnetic Behavior After this reading this section you will be able to do the following: Perform an experiment to detect what materials are magnetic and explain why you think they are magnetic. Magnetism Just like when the Greeks of the old times discovered the first naturally occurring magnetic stones, or natural magnets, you have been [...]
The Two Ends of a Magnet After completing this section you will be able to do the following: Explain what a compass is and how it is affected by a magnet. Understand how a compass helps us to navigate on the earth. Magnets Most people are familiar with the general properties of magnets but are [...]
Types of Magnets Magnets are common in normal life, and almost everyone knows about them. In particular, magnets are known as those materials that have the property of attracting and repelling certain metal materials, such as iron and nickel. However, this is not always the case. Magnets can sometimes lose their magnetic property and thus [...]