Transmission and propagation of electromagnetic waves

1. Looking Back
• Crest
• Amplitude
• Wavelength
• Equilibrium
• Trough

2. ELECTROMAGNETIC
WAVES

3. TWO (2) TYPES OF WAVE
1. Mechanical Waves – waves require a medium to
travel through. They can travel through solid,
liquid and gas.
Example: Sound waves, Seismic waves
2. Electromagnetic Waves – waves that do not
require a medium to travel through. They can travel
in an empty space.
Example: Light waves

4.  A waves that are created as a result of vibrations
between an electric field and a magnetic field.
Composed of oscillating magnetic and
electric field.
A wave is a disturbance that transfers energy.
What is an electromagnetic wave?

5. Heinrich Hertz discovered the Hertzian waves which is
now known as radio waves.
Hertz is the unit used to measure the frequency of waves.
James Clerk Maxwell formulated the Electromagnetic
Wave Theory which says that an oscillating electric
current should be capable of radiating energy in the
form of electromagnetic waves.
Electromagnetic wave

6. EM waves can travel through a vacuum.
EM waves travel at the speed which is constant in a given
medium and has a value of c = 3.0 x 108 m/s in vacuum
EM waves are disturbances in a field rather than in a medium.
Electromagnetic Wave

7.  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.
Electromagnetic Wave

8. Electromagnetic Wave
FALSE

9. TRANSMISSION AND
PROPAGATION OF
ELECTROMAGNETIC
WAVE (EM)

10. OBJECTIVES
A.Describe the transmission and
propagation of electromagnetic
waves.
B.Discuss the properties of EM
waves.

11. WAVE
are disturbances that travel
through space-time, accompanied
by a transfer of energy. It is
characterized by amplitude,
frequency, and wavelength.

12. ELECTROMAGNETIC WAVE
is produced by
oscillating or accelerating
charges.

13. Have you
experience
electromagnetic
waves?

15. Electromagnetic
waves are waves that can travel
through the vacuum of outer
space. Mechanical waves,
unlike electromagnetic waves,
require the presence of a material
medium to transport their energy
from one location to another.

16. The electric and magnetic waves are
perpendicular to each other, and to the
direction of propagation.

17. PROPERTIES OF
ELECTROMAGNETIC
WAVE

18. Properties of Electromagnetic (EM) Wave
can travel through a vacuum
can travel at the speed which is constant in
a given medium and has a value of c= 3.0 x
10 8 m/s in a vacuum
c = speed of light or v = wave speed

19. Properties of Electromagnetic (EM) Wave
Obey the wave equation c=fλ
Wave Speed (m/s)= frequency (Hz) X wavelength
(m)
consist of oscillating electric (E) and magnetic
(B) field vectors at right angles to each other
and at right angles to the direction of
propagation of the wave.
Since all the EM waves have the same
speed(v) which is equal to speed of light(c),
as wavelength decreases, frequency of the
wave increases.

20. Properties of electromagnetic wave (EM)
Wave
have an electric field that travels
perpendicular with the magnetic field.
form when moving charged particles
transfer energy through a field.
are invisible to the eye but detectable. Only
visible light is seen by humans.

21. EM are transverse wave

22. •Lowest point of the wave
Crest •Highest point of the wave
Wavelength
(λ).
•Distance between identical
points on consecutive
waves
Trough
• Number of wave that pass a point
per unit time.
Frequency(
f)
• Height of the wave from origin and
crest 0r trough
Amplitude
• Time between passage of successive crest.
Period

23. ELECTROMAGNETIC SPECTRUM
The electromagnetic Spectrum is
arranged in decreasing wavelength but
increasing frequencies and energy.
They are arranged as follows: radio
waves, microwaves, infrared, visible
light, ultraviolet, X-rays, and gamma
rays.

25. Electromagnetic
waves
are arranged on the
electromagnetic
spectrum
by wavelength,

26. lowest energy waves
have the longest
wavelength and
the lowest
frequency.

27. highest energy waves
have the shortest
wavelength and
the highest frequency.

29. Which has
the longer
wavelength?

30. ACTIVITY TIME:
Pls. do your activities
during our
ASYNCHRONOUS class

32. Electromagnetic Wave Wavelength Range (meters)
Radio Wave
Microwave
Infrared
Visible Light
red
orange
Yellow
green
blue
violet
Ultraviolet
X-ray
Gamma Ray
Using the illustration above, determine the wavelength ranges of each of the forms of
electromagnetic waves.

33. GUIDE QUESTIONS
: 1. Which electromagnetic wave has the longest
wavelength?
2. Which electromagnetic wave has the shortest
wavelength?
3. Observe what happens to the wavelength of the
electromagnetic waves as they progress (goes
rightward from the figure). Does the wavelength of
the EM waves increase or decrease as we go from
radio wave to gamma ray?

35. Electromagnetic Wave Frequency (Hertz)
Radio Wave
Microwave
Infrared
Visible Light
red
orange
Yellow
green
blue
violet
Ultraviolet
X-ray
Gamma Ray
Using the illustration above, determine the wavelength ranges of each of the forms of
electromagnetic waves.

36. GUIDE QUESTIONS
: 4. Which among the EM waves has the highest frequency?
5. Which among the EM waves has the lowest frequency?
6. The energy of an EM wave also depends on its frequency,
which means waves with higher frequency has higher
energy too. Which among the EM waves has the highest
energy?
7. Which among the EM waves has the lowest energy?
8. What happens to the frequency of the electromagnetic
waves as it progresses? Does the frequency of the EM waves
increase or decrease as we go from radio wave to gamma
ray?