Final answer:
Magnets are used in homes to demonstrate magnetic attraction and repulsion, and to stick items like notes to the refrigerator. Permanent magnets have a magnetic field due to aligned magnetic domains. Magnets are also critical in various household devices and technology.
Step-by-step explanation:
Your house needs magnets for a variety of reasons. They can visibly demonstrate the fundamental principles of magnetism, such as the attraction between unlike poles and the repulsion of like poles, which can be tested with refrigerator magnets. These magnets will stick if one is turned over because they are aligning north and south poles in an attracting configuration.
Magnets stick to the refrigerator door as it is typically made of iron or a magnetic form of stainless steel. Objects like metal spoons can be tested for their magnetic properties to see if they contain iron, nickel, or cobalt, which are typically magnetic metals. However, they will not stick to plastic spoons because plastic is not magnetic.
The reason permanent magnets have a magnetic field around them is because of the arrangement of their atomic magnetic domains, which are mostly aligned in one direction in magnetized materials, causing a net magnetic field.
Outside of these simple demonstrations, magnets perform critical functions in various household devices such as electric motors found in appliances, magnetic strips in cards, and in devices that use digital memory. Magnets are a cornerstone in technology and household functionality.