Electromagnetic Waves PDF

Electromagnetic Waves What are electromagnetic waves? Electromagnetic Waves Section 1 slides 3- 31 What are electromagnetic waves? Section 2 slides 32-59 The Electromagnetic Spectrum Section 3 slides 60-69 Radio Communication What are electromagnetic waves? How electromagnetic waves are fo...

Electromagnetic Waves What are electromagnetic waves? Electromagnetic Waves Section 1 slides 3- 31 What are electromagnetic waves? Section 2 slides 32-59 The Electromagnetic Spectrum Section 3 slides 60-69 Radio Communication What are electromagnetic waves? How electromagnetic waves are formed How electric charges produce electromagnetic waves Properties of electromagnetic waves Electromagnetic Waves… Do not need matter to transfer energy. Electromagnetic Waves… Do not need matter to transfer energy. Are made by vibrating electric charges and can travel through space by transferring energy between vibrating electric and magnetic fields. How do moving charges create magnetic fields? Any moving electric charge is surrounded by an electric field and a magnetic field. What happens when electric and magnetic fields change? A changing magnetic field creates a changing electric field. What happens when electric and magnetic fields change? A changing magnetic field creates a changing electric field. One example of this is a transformer which transfers electric energy from one circuit to another circuit. What happens when electric and magnetic fields change? A changing magnetic field creates a changing electric field. One example of this is a transformer which transfers electric energy from one circuit to another circuit.  Inthe main coil changing electric current produces a changing magnetic field  Which then creates a changing electric field in another coil producing an electric current  The reverse is also true. This page was copied from Nick Strobel's Astronomy Notes. Go to his site at www.astronomynotes.com for the updated and corrected version. Making Electromagnetic Waves When an electric charge vibrates, the electric field around it changes creating a changing magnetic field. Making Electromagnetic Waves The magnetic and electric fields create each other again and again. Making Electromagnetic Waves An EM wave travels in all directions. The figure only shows a wave traveling in one direction. Making Electromagnetic Waves The electric and magnetic fields vibrate at right angles to the direction the wave travels so it is a transverse wave. Properties of EM Waves All matter contains charged particles that are always moving; therefore, all objects emit EM waves. Properties of EM Waves All matter contains charged particles that are always moving; therefore, all objects emit EM waves. The wavelengths become shorter as the temperature of the material increases. Properties of EM Waves All matter contains charged particles that are always moving; therefore, all objects emit EM waves. The wavelengths become shorter as the temperature of the material increases. EM waves carry radiant energy. What is the speed of EM waves? All EM waves travel Material Speed 300,000 km/sec in (km/s) space. (speed of light- Vacuum 300,000 nature’s limit!) Air