electromagnetic field
Technical term in physics; used in contexts such as electromagnetism, wave propagation, and field theory.
The theory of electromagnetic fields is described by Maxwell's equations.
この装置は強い電磁場を発生させる。
This device generates a strong electromagnetic field.
磁場 refers specifically to the magnetic field component, while 電磁場 encompasses both electric and magnetic fields.
Compound of 電 (electric) + 磁 (magnetic) + 場 (field), a straightforward calque from English 'electromagnetic field'.