explain hysteresis on the basis of domain theory
Answers
Answer:
We already know that magnets aren't attracted to everything; if we stick a magnet to a wooden wall, it will fall right down. Magnets are generally attracted to objects made of the metals iron, nickel, or cobalt. These are known as ferromagnetic materials.
Explanation:
Magnets stick to these metals because of a special property of the atoms within these metals. The magnetic moments of the atoms inside most other nonmagnetic materials are all oriented in random directions that cancel each other out. Atoms in ferromagnetic materials form structures known as domains. An object may contain multiple domains.
When there is no external magnetic field, the domains are oriented randomly, resulting in no net magnetic field. When an external magnetic field is present, however, the domains rotate and align with the external magnetic field. When all or most of the domains are aligned in the same direction, the entire object is magnetized and becomes a magnet.
Induction is the process of using a magnetic field to magnetize another object. Once induced, a magnet generates its own magnetic field as long as its domains are aligned. A domain is an internal region of a material in which groups of magnetic moments naturally align in the same direction. When the external magnetic field is removed after we have induced a magnet, we can observe an interesting effect. Depending on the material, the domains will remain aligned in the same direction even after the external field has been removed. The domains do not return to normal immediately. This tendency to remain aligned is known as hysteresis. We can make permanent magnets because of hysteresis. To make permanent magnets, we start with a material, shape it into whatever shape we want, and then place it inside a very strong magnetic field. The domains within the material align with the magnetic field, and when the field is removed, the domains remain aligned, and we have created a new magnet.