Wechselmagnetfeld

A Wechselmagnetfeld, or alternating magnetic field, is a magnetic field whose strength and direction change over time. Unlike a static magnetic field, which remains constant, an alternating magnetic field oscillates. This oscillation can be sinusoidal, in which case the field strength follows a sine wave pattern, or it can be a more complex waveform. The frequency of the alternation, measured in Hertz (Hz), indicates how many times the field completes a full cycle of change per second.

Alternating magnetic fields are fundamental to many technologies. In electrical generators, a rotating magnetic field induces an alternating current in stationary coils. Conversely, in electric motors, an alternating current supplied to coils creates an alternating magnetic field that exerts a torque, causing rotation. Transformers rely on the principle of electromagnetic induction, where a changing magnetic field in a primary coil induces an alternating voltage in a secondary coil. This property allows for the efficient stepping up or stepping down of AC voltages.

The generation of alternating magnetic fields is typically achieved by passing an alternating current through a coil of wire. As the current oscillates, the magnetic field it produces also oscillates in strength and polarity. The characteristics of the alternating magnetic field, such as its amplitude and frequency, can be controlled by adjusting the properties of the alternating current. Applications of alternating magnetic fields range from household appliances like induction cooktops and microwave ovens to medical imaging technologies such as MRI (Magnetic Resonance Imaging).