Fyrpolig

Fyrpolig is a Scandinavian term meaning four-pole, derived from the words for four and pole. It is used in Danish, Norwegian, and Swedish to describe objects or components that have four magnetic or electrical poles. The term is primarily found in technical and engineering contexts rather than everyday language.

In electrical machines, fyrpolig describes motors and generators designed with four magnetic poles on the stator or rotor. The pole count influences operating speed: synchronous speed is given by n_s = 120 f / P, where f is frequency and P is the number of poles. At 50 Hz, a fyrpolig (four-pole) machine has a synchronous speed of 1500 rpm; at 60 Hz, 1800 rpm. This affects torque characteristics, efficiency, and the mechanical design of the machine.

In magnetic and accelerator contexts, fyrpolig may refer to magnets with four poles arranged around a circle, with alternating north and south poles. Such four-pole configurations are related to quadrupole magnets, which are used to shape and focus particle beams in accelerators and other specialized equipment.

Usage notes: fyrpolig is a technical term tied to the noun it modifies, and its exact spelling and prevalence can vary between Danish, Norwegian, and Swedish sources. In English-language texts, the equivalent term is typically four-pole or quadrupole, depending on context.

See also: four-pole, quadrupole, multipole.