M10 Flashcards
Ever present all around us is a field or state of energy called
electromagnetic
energy.
The energy exists over a wide range called an
energy continuum.
is an uninterrupted (continuous) ordered sequence. Grouped
together, these types of energy make up the electromagnetic spectrum.
A
continuum
The electromagnetic spectrum contains three different scales.
energy, frequency and wavelength
velocity of all electromagnetic
energy is
constant
the wavelength and frequency are
inversely related. It
should be clear that these three scales are directly related mathematically. If
one knows the value of electromagnetic energy on one scale, one can easily
compute its value on the other two.
The frequency range of electromagnetic energy extends from
102
to 1024 Hz.
The photon wavelengths associated with these radiations are approximately
107 to 10-16 m, respectively.
The known electromagnetic spectrum has three regions important to radiologic
science:
visible light, x- and gamma radiation, and radiofrequency.
Other portions of the spectrum include
ultraviolet light, infrared light, and microwave
radiation.
occupies the smallest segment of the electromagnetic spectrum,
and yet it is the only portion that we can sense directly.
Visible light
Sunlight also contains
two types of invisible light:
infrared and ultraviolet.
consists of photons with wavelengths longer than those of visible
light but shorter than those of microwaves. Infrared light heats any substance
on which it shines. It may be considered radiant heat.
Infrared light
is located in the electromagnetic spectrum between visible light
and ionizing radiation. It is responsible for molecular interactions that can result
in sunburn.
Ultraviolet light
covers a considerable portion of the electromagnetic spectrum and has relatively low energy and long wavelength.
Radiofrequency
