electromagnetic waves
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Electromagnetic Waves. Chapter 12. What is an Electromagnetic Wave?. Electromagnetic wave – is made by vibrating electric charges and can travel through space No medium is needed…. What is an Electromagnetic Wave?. - PowerPoint PPT PresentationTRANSCRIPT
Electromagnetic Waves
Chapter 12
What is an Electromagnetic Wave?
• Electromagnetic wave – is made by vibrating electric charges and can travel through space– No medium is needed…
What is an Electromagnetic Wave?
• Electromagnetic wave – is made by vibrating electric charges and can travel through space– No medium is needed…
• Electric and magnetic fields are related forces.1. A moving electric charge creates a magnetic field2. Changing magnetic fields create changing
electric fields and vice versa
Electromagnetic Fields• Carry radiant energy• Electromagnetic waves travel in a vacuum
(empty space) at 300,000 km/s– they slow as they travel through matter
The Electromagnetic Spectrum• Radio waves• Infrared waves• Visible light
• Ultraviolet light• X rays and gamma rays
Uses of Electromagnetic Spectrum
• Radio waves - Microwaves, Radar, and Magnetic Resonance Imaging (MRI)
• Infrared waves – felt as thermal energy or warmth• Visible light – duh… we see with this light• Ultraviolet waves – kill bacteria and can be absorbed
by fluorescent materials and released as visible light• X rays and gamma rays – provide images of bones,
examines within materials, radiation therapy
Radio Communication
• Radio converts electromagnetic waves into sound waves
Television
• Sounds and images changed into electronic signals broadcast by carrier waves– Carrier wave – a specific frequency in which each
channel is assigned (used in radio too)
Telephones
• Microphone converts sound waves into electrical signal.