What are electromagnetic fields and how can they be described?
Any device connected to an electrical outlet produces an associated electric field, even if the device is switched off. If the device is switched on, a current is flowing producing an associated magnetic field. Both fields are characterized by the quantity of frequency and wavelength. The frequency is the number of waves passing a given point in one second and is measured in units of Hertz (1 Hz = 1 cycle per second). The electromagnetic spectrum covers an enormous range of frequencies. Electric power (50 Hz or 60 Hz) is in the extremely low frequency (ELF) range as well as frequencies below 300 Hz. RF range includes fields with frequencies ranging from about 3 kHz (3000 cycles per second) to 300 GHz (300 billion cycles per second). The radio and TV broadcasting antennas, as well as the cellular telephony antennas radiate radio-frequency E/M fields and the respective part of the spectrum is called radio-spectrum (RF spectrum). The effects caused by the exposure to the E/M radiation mos
