Definition

Noun: A permanent magnet is a piece of magnetic material that retains its own persistent magnetic field after being magnetized. Unlike an electromagnet, it does not require an electric current to maintain its magnetism.

Usage

A "permanent magnet" is used to describe the object itself. It is typically made from materials like ferrite, alnico, or neodymium. - The speaker uses a permanent magnet to convert electrical signals into sound. - She attached the note to the refrigerator door with a small permanent magnet.

Advanced Usage

• Technical Context: In physics and engineering, the strength of a permanent magnet is often described by its remanence (the residual magnetization) and coercivity (its resistance to becoming demagnetized).
  • The design requires a high-coercivity permanent magnet to function reliably in varying temperatures.

Variants and Related Words

• Ferromagnet (n): A material (like iron) that can exhibit strong magnetic properties and can be made into a permanent magnet.
• Magnet (n): The general term for any object that produces a magnetic field. A permanent magnet is a specific type of magnet.
• Lodestone (n): A naturally occurring mineral (magnetite) that is a natural permanent magnet.

Synonyms

• Hard magnet (technical synonym): Emphasizes the magnet's high coercivity and permanent nature.
• Fixed magnet: A less common synonym highlighting its unchanging magnetic field.

Related Phrases

• Permanent magnetic field: The persistent magnetic field surrounding a permanent magnet.
  • The compass needle aligns with the Earth's and the permanent magnetic field of the lodestone.

Noun

1. a magnet that retains its magnetism after being removed from a magnetic field