logging in or signing up ELECTROMAGNETIC SPECTRUM louise.woolford Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 5701 Category: Entertainment License: All Rights Reserved Like it (6) Dislike it (0) Added: July 14, 2009 This Presentation is Public Favorites: 3 Presentation Description No description available. Comments Posting comment... By: deepaasubbu (14 month(s) ago) pretty good Saving..... Post Reply Close Saving..... Edit Comment Close By: soleary61 (22 month(s) ago) i would like to down load this power point for my high school chem class. soleary@mhs,org Saving..... Post Reply Close Saving..... Edit Comment Close By: marben (30 month(s) ago) nice presentation. let me download Saving..... Post Reply Close Saving..... Edit Comment Close By: ravi1369 (36 month(s) ago) i want download it please its nice my email id is "firstname.lastname@example.org" Saving..... Post Reply Close Saving..... Edit Comment Close By: vijay127 (37 month(s) ago) i want to download these slide Saving..... Post Reply Close Saving..... Edit Comment Close loading.... See all Premium member Presentation Transcript Slide 1: JParkinson © 1 THE ELECTROMAGNETIC SPECTRUM Slide 2: JParkinson © 2 ALL ELECTROMAGNETIC WAVES TRAVEL AT THE SPEED OF LIGHT c = 300 000 000 m/s 300 000 000 m / s Slide 3: JParkinson © 3 WAVELENGTH The Electromagnetic Spectrum OUR EYES CAN ONLY SEE A SMALL FRACTION IN THE MIDDLE OF THE WHOLE SPECTRUM LONG WAVELENGTH SHORT WAVELENGTH Which colour has the longer wavelength, red light or blue light? Which colour has the greater frequency, red light or blue light? Slide 4: JParkinson © 4 THE FREQUENCY OF A WAVE IS THE NUMBER OF WAVES EMITTED PER SECOND Frequency, f, is measured in HERTZ Hz Slide 5: JParkinson © 5 The speed at which the crests move along, c, the frequency of the waves and their wavelength are related by the formula: c = f ? velocity = frequency times wavelength = c f x ? Slide 6: JParkinson © 6 The Electromagnetic Spectrum WAVELENGTH INCREASING FREQUENCY INCREASING HIGH FREQUENCY RADIATIONS TEND TO BE MORE PENETRATING ELECTROMAGNETIC RADIATION COMES IN BURST CALLED PHOTONS Slide 7: JParkinson © 7 Gamma Ray photon; wavelength 10-11 – 10-13 metres, i.e. about a million millionth of a metre APPLICATIONS: sterilizing medical equipment in hospitals pasteurizing certain foods to prolong shelf life treatment of cancer gauge the thickness of metal in steel mills radiography – patient ingests radioactive source, whereabouts in the body is then located with a gamma camera Slide 8: JParkinson © 8 X Ray photon; wavelength 10-9 – 10-11 metres, i.e. about a billionth of a metre… about the size of an atom APPLICATIONS: radiography treatment of cancer cells airport security checks studying atomic and molecular structure ….. X-Ray crystallography Slide 9: JParkinson © 9 Ultra Violet light wavelength 10-7 – 10-8 metres, i.e. about a ten millionth of a metre… the size of a virus APPLICATIONS: criminology…. some stains [e.g. blood] fluoresce under uv light security marking detection and destruction of bacteria phototherapy treatment of skin complaints, e.g. psoriasis Slide 10: JParkinson © 10 VISIBLE LIGHT wavelength about 0.5 micrometres [µm] or half a millionth of a metre Protazoa size Slide 11: JParkinson © 11 wavelength about 1mm to 1µm INFRA RED APPLICATIONS: night-time surveillance medical: CO2 laser surgery & thermal imaging weather forecasting remote controls heat seeking missiles Slide 12: JParkinson © 12 Wavelength: a few centimetres microwaves & radar APPLICATIONS: radar inc. weather forecasting cooking telecommunications inc. mobile phones Slide 13: JParkinson © 13 TV & RADIO APPLICATIONS & WAVELENGTHS: Ultra High Frequency - UHF for TELEVISION …… about 10 cm Very High Frequency - VHF for FM RADIO ……. about 1 metre Short Wave – SW … AM Radio …… 10m & 50m bands Medium Wave – MW … AM Radio …… 200 to 600m Long Wave – LW … AM Radio …… 1000 to 2000m You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.