EM waves are a group of transverse waves that consist of electric and magnetic fields oscillating perpendicular to each other. They travel at a constant velocity (c) of nearly 186,282 miles per second or about 299,792,458 meters per second (m/s) in a vacuum. The electromagnetic (EM) spectrum depicts the entire range of EM waves in order of their frequency or wavelength, beginning with direct current (DC) and ending with gamma rays. Each band of the spectrum possesses distinct characteristics and are classified into seven categories based on their frequency and wavelength.
EM wave bands have a wide range of technological applications, ranging from communication and household activities to remote sensing and medical imaging and treatment. Additionally, EM wave bands of different wavelengths or frequencies are used in various spectroscopic applications, including nuclear magnetic resonance (NMR), electron spin resonance (ESR), rotational and vibrational spectroscopy, microwave spectroscopy, infrared spectroscopy, visible spectroscopy, ultraviolet (UV) spectroscopy, X-ray spectroscopy, and gamma-ray spectroscopy. These techniques provide insights into how atoms or molecules in a material undergo transitions when exposed to different EM energy bands.
Dielectrics are non-conductive materials that become polarized when subjected to an electric field. The process of polarization is what causes dielectrics to exhibit conductive behavior. Dielectrics differ from insulators in that while insulators do not permit the flow of current through them, dielectrics tend to accumulate charges within them when subjected to an electric field
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