Science W2A - Practical Applications of Different Regions of EM Waves Flashcards
is a continuous range of electromagnetic waves arranged in order of frequency or wave length
electromagnetic spectrum
have the longest wavelengths (10⁴m–10^-1m) and shortest frequencies (3.0×10⁴–3.0×10¹² or from 30kHz to 3000 MHz)
radio waves
can be longer than a football field or as short as a football
radio waves
most suitably usable in communication devices across all platforms
radio waves
discovered radio waves in 1887
Heinrich Hertz
Type of frequency (radio): long distance communication and navigation
low frequency
Type of frequency (radio): amplitude modulation (AM) radio broadcasting
medium frequency
Type of frequency (radio): shortwave broadcasting, tags for use and building access, public transportation, and electronic payment systems
high frequency
Type of frequency (radio): frequency modulation (FM) radio broadcasting, ground-to-aircraft and aircraft-to-aircraft communication
very high frequency
Type of frequency (radio): police radio communication, military aircraft and television transmission, modern cell phones, and global positioning system
ultra high frequency
have longer wavelengths (180-550 meters), and radio stations change the amplitude of radio waves to transmit audio information
amplitude modulation (AM)
uses short radio waves (2.8-3.4 meters) and modulates the frequency of the carrier signal for broadcasting
frequency modulation (FM)
use radio waves for detection of objects, weather forecasting, military surveillance, air traffic control, monitoring speed in highway patrol and tracking satellites and debris
radar (radio detection and ranging)
locates positions within a 10- to 100-m accuracy
GPS (global positioning system)
can store and transmit data, similar to the universal product code (UPC) or bar code that is seen on grocery items
RFID (radio frequency identification)
is a rate of oscillation in the range of about 3kHz to 300Ghz
radio frequency (RF)
used for viewing internal parts of the human body without invasive exploratory surgery
MRI (magnetic resonance imaging)
This region lies somewhere between 3×10⁸ Hz and 3×10¹¹ Hz, which is from 300 MHz to 300 GHz, with a wavelengths of 10^-3–10^-1
microwave
are part of the electromagnetic spectrum lying between radio waves and infrared with short wavelengths (1mm-30cm) and high frequencies
microwaves
named as their waves are very short compared to radio waves
microwaves
discovered microwaves in 1864
James Clerk Maxwell
microwave radars used in weather forecasting
Microwave Doppler
kitchen appliance that uses 2.45 GHz microwaves to cook food
microwave oven
Microwave ________ uses the heat of microwaves to shrink or destroy tumors.
microwave ablation
Microwave _______ is used to assess and monitor progress of treatment of breast cancer via microwave tomography.
microwave imaging
literally means ‘below red’ and lies between microwaves and visible light with frequencies ranging from 3×10¹¹–4×10¹⁴ Hz and wavelengths of 7.5×10^ to 10^-3 m
infrared radiation
cannot be seen but felt as heat
infrared radiation
wavelength longer than visible light and includes most of the thermal radiation emitted by objects near room temperature
infrared radiation
used to remotely determine the temperature of an object (thermography or pyrometry)
infrared
two types of infrared radiation
near infrared and far infrared
closest in wavelength to visible light; give an example
near infrared - remote control
closest in wavelength to microwave; give three examples
far infrared - sunlight, fire, or radiator
discovered infrared radiation in 1800
Sir William Hershel
_______ infrared _______ is used for diagnosis and prognosis in oncology, rheumatology, sports medicine, and orthopedics.
Medical infrared imaging
The portion of EM radiation that is visible to the human eye, occupying a small portion of the spectrum with frequency 4×10¹⁴–8×10¹⁴ Hz and wavelengths from 4×10^-7–8×10^-7 m
visible light
sequence of colors of visible light
red, orange, yellow, green, blue, indigo, violet
color separated in modern usage
indigo
color with the longest wavelength and lowest frequency
red
color with the shortest wavelength and highest frequency
violet
most energetic color
red
color with least amount of energy
violet
emerging form of wireless communication technology using light-emitting diodes (LED)
visible light communication (VLC)
one source of visible light that is used in many medical procedures like optical imaging, surgery, endoscopy, and treatment, as well as biomedical research and microscopy
laser (light amplification by the stimulated emission of radiation)
discovered the range of wavelength in the visible light spectrum in 1666
Isaac Newton
literally means ‘above violet,’ its wavelengths 6×10^-10–4×10^-7 are shorter than visible light but longer than x-rays; frequencies 8×10¹⁴–10¹⁷ Hz
ultraviolet radiation
three kinds of ultraviolet rays
UVA, UVB, and UVC
has wavelengths 315 nm to 400 nm; 95% of the solar UV reaching earth; less intense but penetrates the skin more deeply (reaching the dermis); reaches the lens and retina and causes cataract and retinal diseases
UVA
has wavelengths 280 nm to 314; filtered by the ozone in the atmosphere; affects the topmost layer (epidermis) of the skin; causes skin to darken and skin cancer
UVB
has wavelengths 60 nm to 279 nm; almost completely absorbed by the atmosphere and does not reach the earth’s surface; most damaging
UVC
major source of UV rays
sun
also known as black light
ultraviolet light
used to treat skin conditions such as psoriasis and vitiligo that causes depigmentation of the skin
UVA
overexposure may lead to skin cancer, melanoma, and eye problems (photo keratitis)
ultraviolet radiation
discovered ultraviolet radiation in 1801
Johann Wilhelm Ritter
high-energy waves that are used extensively in medical applications, lying beyond the UV region with wavelengths 10^-12–10^-8
x-rays
X-ray is also called?
Roentgen ray
How was x-ray named?
Roentgen couldn’t name them as he did not know their nature and origin, thus naming it the variable “x.”
given off by radioactive elements such as cobalt-60 and cesium-137
gamma rays
sources of gamma rays
sun, interstellar clouds, and remnants of supernova
employed in the refining, mining, chemical, food, and soap and detergent industries, as well as pulp and paper industries to control volume level, density, and thickness
noncontact industrial sensors
kills bacteria, insects, and parasites that can cause foodborne diseases
food irradiation
may be internal or external
radiotherapy
The patient is exposed to a beam of radiation.
external radiotherapy
Sometimes called brachytherapy, radiation comes from implant or liquids placed inside the body.
internal radiotherapy
discovered gamma rays in 1900
Paul Villard
two classifications of x-ray
soft and hard
x-rays with lower energy level and can penetrate flesh and bones
soft x-rays
x-rays with higher energy level and more penetrating
hard x-rays
produce x-rays
sun and other stars
produced when accelerated atoms hit a metal and some medical equipment
x-rays
takes photographs of internal body parts
CAT or CT scan
X-rays used this to identify crystal structure of materials.
crystallography
discovered x-rays in 1901
Wilhelm Conrad Roentgen
highly penetrating because of their very short wavelengths 10^-14–10^-10 m, generated by radioactive atoms and in nuclear explosions, and are used in many medical applications
gamma rays
