vaihtovirtakenttiä

Vaihtovirtakenttiä, known in English as alternating current (AC) fields, refers to a type of electromagnetic field that periodically reverses direction. This phenomenon is fundamental to the generation, transmission, and utilization of alternating current electricity. Unlike direct current (DC) which flows in a single direction, AC fields oscillate. This oscillation is characterized by a frequency, measured in Hertz (Hz), indicating how many times the field completes a full cycle of change in direction per second. Common frequencies for AC power grids are 50 Hz or 60 Hz.

The creation of an AC field typically involves a changing electric current. According to Faraday's law of induction, a changing magnetic field can induce an electric field, and conversely, a changing electric field can induce a magnetic field. This interconnectedness is the basis of electromagnetic waves and AC phenomena. Generators produce AC by rotating coils of wire within a magnetic field, thereby inducing a continuously changing voltage and current, which in turn creates a fluctuating magnetic field. Transformers exploit the properties of AC fields to efficiently step voltage up or down for transmission and distribution. The direction of the electric and magnetic components within an AC field are perpendicular to each other and to the direction of wave propagation.