The Various Shapes of Magnets and Their Uses
Magnets come in a variety of shapes and sizes like disc, sphere, horseshoe and a number of other unique forms. Usually, bigger magnets are stronger, but now always. Small magnets can be improved to increase strength by using different materials. The shape of a magnet, however, can tell you a lot more than size. Each magnet’s shape has an influence how it is used. It determines how the magnetic field lines are arranged outside of the magnet as well as the strength of its pull. What are some of the common shapes of magnets and how are they used?
A magnet’s power is focused at the poles and lessens at the sides. Bar magnets are generally the weakest shape, because the poles have the smallest area. They are, however, the most common shape used in everyday life such as refrigerator magnets and compasses.
Bar magnets are also commonly used for demonstrations in the classroom. For example, you can use the bar magnet to reveal a magnetic field by spreading metal shavings on a piece of paper concealing a magnet.
Horseshoe magnets are just bar magnets bent in a U shape. The U shape makes the magnet stronger by pointing the poles in the same direction. Originally created as a replacement for the bar magnet, this shape has become the universal symbol for magnets. It can be used to pick up metal objects of any size depending on the strength of the horseshoe magnet. For example, small horseshoes can collect paper clips while industrial-sized horseshoe magnets are used in construction and engineering to pick up large pieces of heavy metal. Horseshoe magnets are also used at the bottom of pendulums.
We can manipulate a magnet’s shape to increase the area of the poles, thereby increasing the strength of its pull. Because of the wide, flat surface, disc magnets have a large pole area making them strong, effective magnets.
Depending on the size of the disc, this shape has a variety of uses. Disc magnets are used every day in clothing, fashion accessories, and home decor. Sewing disc magnets into clothing is a great way to hold fabric together. Industrial-sized disc magnets are commonly used to pick up old cars at junkyards. Breaking Bad fans may recognize this magnet from the season 5 premiere when a junkyard disc magnet is used to destroy the hard drive of a laptop from a distance.
Sphere magnets are often sold as toys and novelty items. Sphere magnets make popular desk toys such as Rattlesnake Eggs. This shape can also be used to create bracelets and necklaces. Spherical magnets are also effective tools when demonstrating how some elements and molecules are structured if you use the spheres to represent atoms.
Cylinder magnets are sometimes used in medicine. According to BBC News, some doctors experiment with magnetic rods to treat scoliosis patients. Unlike metal rods, magnetic rods can be lengthened noninvasively by remote control even after the rods have been placed in the patient’s spine. This eliminates the need for multiple surgeries to lengthen the rod during treatment.
Ring magnets are usually used in science experiments such as a demonstration of magnetic repulsion where the magnetic rings are threaded through a wooden pole. When the same poles of the magnets face each other they won’t touch.
Ring magnets are also occasionally used in medicine. For example, some studies have shown that they neutralize Implantable cardioverter-defibrillators (ICD) if they malfunction. ICDs correct the heart’s rhythm with an electric shock if it becomes irregular. Sometimes the ICD malfunctions and can apply more shocks than are needed, which can be fatal for the patient unless a ring magnet is applied to the patient’s chest.
Magnets come in a variety of shapes and sizes and are used every day in your home as well as in classrooms, science labs and hospitals. While shape often determines the function of a magnet, don’t limit yourself to a magnet shapes common functionality - use your imagination! How do you use different magnet shapes? Leave a comment and let us know!