Electromagnetic waves are transverse waves that consist of oscillating electric and magnetic fields and propagate through space carrying energy. They include radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays differing in wavelength and frequency. Electromagnetic waves travel at the speed of light and have both electric and magnetic field properties. Common applications of different types of electromagnetic waves include using radio waves for communication, microwaves for cooking, visible light for sight, ultraviolet light for sterilization, X-rays for medical imaging, and gamma rays for radiation treatment.

1. Electro magnetic waves
Presented by
MD. Abdur Rahman
ID: 1402EEE00019
2nd Batch
Dept of EEE (EEE)

2. What is Electro magnetic waves
 The wave of the electric field and the wave of the magnetic field
are propagated perpendicularly to the direction of propagation and
to each other. At extremely low frequencies, the electric field and
the magnetic field are specified separately. At higher frequencies,
electric and magnetic fields are not separable, and are named
"electromagnetic waves" or "electromagnetic fields".

3. Nature of Electromagnetic Waves
They are Transverse waves without a medium. (They can travel through
empty space)
They travel as vibrations in electrical and magnetic fields.
Have some magnetic and some electrical properties to them.
Speed of electromagnetic waves = 300,000,000 meters/second (Takes
light 8 minutes to move from the sun to earth {150 million miles} at this
speed.)

4. Layers of the Ionosphere

5. Types of Electromagnetic Waves
X-ray.
Gamma rays.
 Ultraviolet.
 Visible light (ROYGBV).
 Infrared.
 Microwave.
 Radio wave.

6. X- RAYS
 Shorter wavelength and higher frequency than UV-rays
 Carry a great amount of energy
 Can penetrate most matter.
 Bones and teeth absorb x-rays. (The light part of an xray image indicates a place where the x-ray was absorbed)
 Too much exposure can cause cancer
 (lead vest at dentist protects organs from unnecessary exposure)
 Used by engineers to check for tiny cracks in structures.
 The rays pass through the cracks and the cracks appear dark on film.

7. GAMMA RAYS
 Shorter wavelength and higher
frequency than X-rays
 Carry the greatest amount of energy
and penetrate the most.
 Used in radiation treatment to kill
cancer cells.
 Can be very harmful if not used
correctly.

8. Ultraviolet ray
 Shorter wavelength and higher frequency than
visible light .
 Carry more energy than visible light.
 Used to kill bacteria. (Sterilization of equipment).
 Causes your skin to produce vitamin D (good for
teeth and bones) .
 Used to treat jaundice ( in some new born babies).
 Too much can cause skin cancer.
 Use sun block to protect against (UV rays).

9. RADIO WAVES
 Have the longest wavelengths and lowest frequencies of
all the electromagnetic waves.
 A radio picks up radio waves through an antenna and
converts it to sound waves.
 Each radio station in an area broadcasts at a different
frequency. # on radio dial tells frequency.

10. Microwave.
 Microwaves—have the shortest wavelengths and the highest frequency of the radio waves.
 Used in microwave ovens.
 Waves transfer energy to the water in the food causing them to vibrate which in turn transfers energy in the
form of heat to the food.
 Used by cell phones and pagers.
 RADAR (Radio Detection and Ranging)

12. Thank you