Context:
Invented in 1824 by William Sturgeon, electromagnets are a fixture of modern life, appearing in loudspeakers, motors, magnetic resonance imaging (MRI) machines, maglev trains, and particle accelerators.
Relevance:
Facts for Prelims
About Electromagnets:
- Definition: Electromagnets are devices that generate a magnetic field when an electric current flows through a coil of wire.
- Magnetic Field: The magnetic field is concentrated within the coil. The strength of this field can be adjusted by modifying the electric current. When the current stops, the magnetic field vanishes.
- Construction and Materials: Typically, electromagnets consist of a wire coil wrapped around a core made of ferromagnetic materials like iron. The core enhances the magnetic field’s strength by aligning its magnetic domains.
- Control: Electromagnets can be activated or deactivated by controlling the electric current.
- Power: They are more powerful than permanent magnets because the magnetic field can be intensified by the magnetic core.
- Applications: They are commonly used in various devices such as motors, generators, MRI machines, and magnetic separation equipment.
- Industrial Uses: Electromagnets are utilized in industries for lifting and moving heavy metal objects, sorting materials, and generating motion.
- Medical and Consumer Uses: They are also used in medical imaging and consumer devices like electric doorbells and card readers.
- Energy Requirement: Electromagnets need a continuous supply of electrical power to maintain their magnetic field. As a result, they are less energy-efficient compared to permanent magnets.
-Source: The Hindu
