The electromagnetic spectrum
Download
1 / 17

The Electromagnetic Spectrum - PowerPoint PPT Presentation


  • 79 Views
  • Uploaded on

The Electromagnetic Spectrum. PHYSICS 1. Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India http://www.cts.iitkgp.ernet.in/~phy1/. Radio wave. Less than 1 GHz. Microwave. 1 GHz to 3  10 11 Hz. 30 cm to 1 mm.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' The Electromagnetic Spectrum' - brice


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
The electromagnetic spectrum
The Electromagnetic Spectrum

PHYSICS 1

  • Somnath Bharadwaj and Pratik Khastgir, Department of Physics and Meteorology, IIT Kharagpur, 721 302 India

    http://www.cts.iitkgp.ernet.in/~phy1/


Radio wave
Radio wave

Less than 1 GHz


Microwave
Microwave

1 GHz to 3  1011 Hz

30 cm to 1 mm


Space communication
Space communication

Atmosphere is transparent from

less than 1 cm to 30 m

Also suitable for radio astronomy




Radio interferometric arrays
Radio Interferometric Arrays

32 MHz bands with 128 separate channels


Hi in galaxies
HI in Galaxies

DDO 210 Source: Begum and Chengalur

Dwarf Irregular Galaxy




Molecular rotations
Molecular Rotations

Water 2.45 GHz used in microwave ovens

Excites Rotations of water molecules

50 GHz to 10 THz T-rays


Infrared
Infrared

3  1011 Hz to 4  1014 Hz

Near IR 760 - 3000 nm

Intermediate IR 3000 - 6000 nm

Far IR 6000 - 15000 nm

Extreme IR 15000nm – 1 mm

Human body peaks at 10000 nm


Visible light
Visible Light

3.84  1014 Hz to 7.69  1014 Hz

Mainly atomic transitions – outer levels

Hot bodies ~5000K


Ultraviolet
Ultraviolet

8  1014 Hz to 3  1016 Hz

Enough energy to ionize atoms in upper atmosphere

Is harmful – absorbed by O3 in upper atmosphere

Produced in energetic atomic transitions


X ray
X-ray

2.4  1016 Hz to 5  1019 Hz

Energetic electrons incident on a metal

Hot astrophysical sources – Black Holes

Inner shell transitions in atoms


Centaurus cluster
Centaurus Cluster

Credit: J. Sanders, A. Fabian,


Gamma rays
Gamma Rays

Frequency greater than 5  1019 Hz

Produced in nuclear transitions

Electron-positron annihilation

Easy to detect – ionizes gas


ad