Magnets are used for a variety of applications. From your common refrigerator magnet to the magnets used in MRI machines, they can be both entertaining and practical. The strength of a magnetic field is measured in either gauss or tesla units.
Types of Magnets
Magnets come in two types: Permanent magnets will have a magnetic field no matter what happens to them. Electromagnets are metals that only have a magnetic field when an electric current runs through them. Some soft metals can become temporarily magnetized in the presence of a magnetic field, but once the field is gone, they are no longer magnetic. Standard magnets, like fridge magnets, are permanent magnets.
Measuring Magnetic Strength
The strength of a magnetic field is typically measured in either gauss or tesla units. One tesla equals 10,000 gauss. Magnometers, gaussmeters or pull-testers are all used to gauge the strength of a magnet.
Standard Magnet Strength
According to the National High Magnetic Field Laboratory of Florida State University, a fridge magnet is about 0.001 tesla. To put that in perspective, the Earth's magnetic field is about 0.00005 tesla and an average MRI magnet measures 1.5 tesla.
References
About the Author
Melissa Monks began writing professionally in 2003 and spent four years writing for the Beutler Heating and Air company newsletter. She also spent two years as a content director for StoryMash.com, publishing projects and blogs, and has worked as a research assistant for One On One, a company publishing educational material. Monks received a Bachelor of Arts degree in English from the University of Utah.
Photo Credits
magnet attracting dollar signs image by Steve Johnson from Fotolia.com