Electromagnetic Spectrum - PowerPoint PPT Presentation

Loading...

PPT – Electromagnetic Spectrum PowerPoint presentation | free to download - id: 6c45c7-ZWY1M



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Electromagnetic Spectrum

Description:

Electromagnetic Spectrum Created by Dr. A. Davila – PowerPoint PPT presentation

Number of Views:11
Avg rating:3.0/5.0
Slides: 49
Provided by: Anit63
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Electromagnetic Spectrum


1
Electromagnetic Spectrum
  • Created by Dr. A. Davila

2
In the above diagram the white line represents
the position of the medium when no wave is
present.
http//id.mind.net/zona/mstm/physics/waves/partsO
fAWave/waveParts.htmfrequency
3
http//id.mind.net/zona/mstm/physics/waves/partsO
fAWave/waveParts.htmfrequency
4
http//id.mind.net/zona/mstm/physics/waves/partsO
fAWave/waveParts.htmfrequency
5
http//id.mind.net/zona/mstm/physics/waves/partsO
fAWave/waveParts.htmfrequency
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
Radio Waves
  • Are produced by feeding an electric signal to the
    mast or antenna of a transmitter.

10
Radio Waves
  • Radio waves have the longest wavelengths in the
    electromagnetic spectrum.
  • These waves can be longer than a football field
    or as short as a football.

11
Radio Waves
  • Radio waves have the longest wavelengths in the
    electromagnetic spectrum.
  • These waves can be longer than a football field
    or as short as a football.

12
Radio Waves
  • The signal makes the electrons in the metal
    atoms of the mast or antenna change energy levels
    and emit light rays.

13
RAYS TV reception uses radio_ waves The
SATELITE_ at Rays TV receives movies via radio
waves from a satellite TAXI_ - Car radio receives
radio wave signals TAXI_ - Driver receives
instructions on a CB radio which uses radio
waves. RADIO TOWER - broadcasts radio signals
LARGE SATELITE _ dish in field receives radio
waves from distant stars
14
3
8
5
0
15
3
8
5
100,000 m
0
1 m
16
3
1000 m
8
100000000 m
5
100,000 m
0
1 m
17
Microwaves
  • Microwaves have wavelengths that can be measured
    in centimeters
  • The longer microwaves, those closer to a foot in
    length, are the waves which heat our food in a
    microwave oven

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
18
Microwaves
  • Microwaves are good for transmitting information
    from one place to another because microwave
    energy can penetrate haze, light rain and snow,
    clouds, and smoke.

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
19
Microwaves
  • Shorter microwaves are used for radar like the
    doppler radar used in weather forecasts.
    Microwaves, used for radar, are just a few inches
    long.

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
20
MICROWAVES in Wavesgrill uses microwave to cook
food. Antennas on tower they send microwave
communications
21
9
8
-2
22
9
1000000000 m
8
100000000 m
-2
0.01 m
23
Infrared Waves
  • The longer, far infrared wavelengths are about
    the size of a pin head and the shorter, near
    infrared ones are the size of cells, or are
    microscopic.

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
24
Infrared Waves
  • The heat that we feel from sunlight, a fire, a
    radiator or a warm sidewalk is infrared.
  • Shorter wavelengths are the ones used by your
    TV's remote control.

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
25
Infrared Waves
  • Satellites like GOES 6 and Landsat 7 look at the
    Earth. Special sensors, like those aboard the
    Landsat 7 satellite, record data about the amount
    of infrared light reflected or emitted from the
    Earth's surface.

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
26
Infrared lights above food in Wavesgrill use
infrared waves to keep food hot Infrared remotes
- Remote controls use infrared waves to
communicate with the TV Trees, brashes, crops,
and short vegetation reflects short infrared
waves Astronomers study thermal infrared (long
infrared waves) from stars
27
11
12
-3
28
11
100000000000 m
12
1000000000000 m
-3
0.001 m
29
Visible Spectrum
  • Cones in our eyes are receivers for these tiny
    visible light waves.
  • The Sun is a natural source for visible light
    waves and our eyes see the reflection of this
    sunlight off the objects around us.

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
30
Visible Spectrum
  • The color of an object that we see is the color
    of light reflected. All other colors are
    absorbed.
  • Light bulbs are another source of visible light
    waves.

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
31
VISIBLE LIGHT Water droplets cause white light
to break apart into seven colors (Visible
Light). Portrait photographers use film
sensitive to visible light Astronomers look at
visible light from planets and stars
32
14
15
-6
33
14
100000000000000 m
15
1000000000000000 m
-6
0.000001 m
34
(No Transcript)
35
Ultraviolet Waves
  • Astronomers have to put ultraviolet telescopes on
    satellites to measure the ultraviolet light from
    stars and galaxies - and even closer things like
    the Sun

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
36
A tanning booth uses ultraviolet waves to tan our
skin ultraviolet waves - sunglasses protect our
eyes from the ultraviolet waves Sunblocks -
protects our skin from ultraviolet
waves ultraviolet waves astronomers see some
ultraviolet radiation from planets and stars
37
15
17
-8
38
15
1000000000000000 m
17
100000000000000000 m
-8
0.00000001 m
39
X-Rays
  • X-ray light tends to act more like a particle
    than a wave. X-ray detectors collect actual
    photons of X-ray light.
  • The Earth's atmosphere is thick enough that
    virtually no X-rays are able to penetrate from
    outer space all the way to the Earth's surface.

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
40
X-Rays
  • X-ray telescopes and detectors are placed on
    satellites. We cannot do X-ray astronomy from the
    ground can not be done from Earth
  • comets emit X-rays
  • The Sun also emits X-rays
  • Many things in deep space give off X-rays

Images from http//science.hq.nasa.gov/kids/imag
ers/ems/gamma.html
41
17
19
-10
42
17
10000000000000000 m
19
10000000000000000000 m
-10
0.0000000001 m
43
At EMS, Dr. Bob uses X-ray detectors collect
actual photons of X-ray light in his
Clinic. Nuclear Medicine is used to treat
cancer. Gamma radiation kills sick cells.
44
Gamma Rays
  • Gamma-rays are generated by radioactive atoms and
    in nuclear explosions
  • They can kill living cells, a fact which medicine
    uses to its advantage, using gamma-rays to kill
    cancerous cells.

http//science.hq.nasa.gov/kids/imagers/ems/gamma.
html
45
Gamma Rays
  • .Gamma-rays travel to us across vast distances of
    the universe,
  • Instruments aboard high-altitude balloons and
    satellites like the Compton Observatory provide
    our only view of the gamma-ray sky

46
19
23
-12
47
19
1000000000000000000 m
23
100000000000000000000000 m
-12
0.000000000001 m
48
(No Transcript)
About PowerShow.com