Q:

What is the difference between a permanent and temporary magnet?

A:

Quick Answer

A permanent magnet is one that retains its magnetic properties for a long period of time. A temporary magnet only maintains its magnetism while in the magnetic field produced by a permanent magnet or an electric current.

Know More
What is the difference between a permanent and temporary magnet?
Credit: Hitchster CC-BY 2.0

Full Answer

The materials from which permanent magnets are made are called hard magnetic materials, and typically consist of iron, nickel, cobalt and some rare earth alloys. Once magnetized, these materials tend to maintain their magnetism for long periods of time. The materials that form temporary magnets are known as soft magnetic materials, and consist of materials like annealed iron. The main difference between hard and soft magnetic materials is their coercivity, or the threshold an external magnetic or electric field would have to exceed in order to demagnetize the material. Hard magnetic materials have a much higher coercivity than soft magnetic materials.

Learn more about Magnetism

Related Questions

  • Q:

    Who first discovered a substance with magnetic properties?

    A:

    The National High Magnetic Field Laboratory notes that the discovery of a substance with magnetic properties is not attributed to one person. Ancient Greeks first mentioned that lodestone had magnetic properties around 600 BC. Thales of Miletus, a philosopher, noted that lodestone, also known as magnetite, attracts iron.

    Full Answer >
    Filed Under:
  • Q:

    How do electromagnets work?

    A:

    Electromagnets are intriguing devices that create a magnetic field using electricity and do not always exhibit magnetic properties. These types of magnets function by running a current from some source of electricity through a wire. This simple process can create a magnetic field around another coiled wire, which causes the electromagnet to exhibit the desired behavior and properties as though it has been magnetized.

    Full Answer >
    Filed Under:
  • Q:

    How long do magnets last?

    A:

    The magnetic field of a permanent magnetic material destabilizes on its own over a long period of time, generally on the order of hundreds of years. Magnets, however, weaken more quickly when they are exposed to physical shocks, other magnetic or electrical fields, and high temperatures.

    Full Answer >
    Filed Under:
  • Q:

    How do you demagnetize?

    A:

    To demagnetize a magnet, heat, hammer or jar the magnet, or use an alternating current field. Tools known as demagnetizers also exist that are used to demagnetize screws and steel tools. Magnetism is the result of alignment of magnetic dipoles in material in a direction.

    Full Answer >
    Filed Under:

Explore