The document discusses electromagnetic waves, explaining their formation, speed, and relationship between wavelength, frequency, and energy. It outlines various types of electromagnetic radiation, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays, detailing their properties and uses. Additionally, it highlights the work of pioneering scientists like James Clerk Maxwell and Heinrich Hertz in understanding and discovering these waves.

1. SCIENCE 10
Quarter 2
Week 1

2. LET’S
DISCOVER

3. ELECTROMAGNETIC
WAVES

4. OBJECTIVE/S: Compare the relative
wavelengths of different forms of
electromagnetic waves (S10FE-IIa-b-47);
Subtask:
1.Identify the relationship among
wavelength, frequency and energy of
an electromagnetic wave.
2. Determine the different forms of EM
waves.
3. Cite situations that applies EM
waves.

5. DIFFERENT FORMS
OF
ELECTROMAGNETIC
RADIATION

6. ELECTROMAGNETIC WAVES
are waves which can travel
through the vacuum of outer
space .
are formed when an electric field
couples with a magnetic field.
The magnetic and electric fields
of an electromagnetic waves are
perpendicular to each other and
to the direction of waves.”

7. What is the speed of EM
waves?
•EM waves travel at the speed
which is constant in a given
medium and has a value of
c=3.0 x 10 m/s in vacuum.
•EM waves usually travel
slowest in solids and fastest in
gases
8

8. Cont.
 the wave speed, frequency, and
wavelength are related by the
following equation:
v= f
ƛ
Where;
v is the wave speed or c (speed of light)
is expressed in meters per second
f for frequency which is expressed in
Hertz
for wavelength expressed in meters
ƛ

9. EXAMPLE PROBLEMS:
(Assume that the waves propagate in a
vacuum)
1. What is the frequency of radio waves
with wavelength of 20 m?
Given: v = c= 3 x 10 m/s f=?
= 20 m
ƛ
Equation: v=c= f f = c/
ƛ ƛ
Solution:
f = c/ƛ
= 3x10 m/s
20 m
= 1.5 x 10 Hz
8
8
7

10. 2. What is the frequency of light waves with
wavelength of 5 x10 m?
Given: v = c = 3 x 10 m/s f=?
= 5 x10 m
ƛ
Equation: v=c= f f = c/
ƛ ƛ
Solution:
f = c/ƛ
f = ?
-7
8
-7

11. 2. What is the frequency of light waves with
wavelength of 5 x10 m?
Given: v = c = 3 x 10 m/s f=?
= 5 x10 m
ƛ
Equation: v=c= f f = c/
ƛ ƛ
Solution:
f = c/ƛ
= 3x10 m/s
5x10 m
= 6 x10 Hz
-7
8
8
-7
-7
14

12. RADIATION
 is an energy that comes
from a source and travels
through space and may be
able to penetrate various
materials

13. Electromagnetic Radiation
is a radiant energy coming from the sun.
It is one of energies present in the universe.
This energy is produced through nuclear
reactions in the sun’s core which streams
from its surface in waves of different
wavelength. The shortest and the longest
wavelength are invisible to the eye but
medium wavelength is visible radiation we
call sunlight.
All substances give off electromagnetic
radiation in the form of electromagnetic
waves.

14. PIONEERING SCIENTIST
 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.
 Heinrich Hertz
- discovered the Hertzian waves which
is now known as radio waves.

15. TYPES OF EM WAVES
1. Radio waves
2. Microwaves
3. Infrared waves
4. Visible light
5. Ultraviolet
6. X-rays
7. Gamma rays

16. ACTIVITY

17. KEY CONCEPT
Wavelength is the distance
between crest to crest or trough
to trough. EM waves are bounded
at different ranges. Meaning each
type of EM waves has upper and
lower limits on the spectrum.

18. Directions:
Using the illustration on the next
slide, determine the wavelength
ranges of each of the forms of
electromagnetic waves. On a
separate sheet of paper, copy and
answer the given table. Afterwards
answer the questions that follow.

19. Study the illustration below

21. Processing Questions:
Q1.Which electromagnetic wave has the
longest wavelength?
Q2.Which electromagnetic wave has the
shortest wavelength?
Q3.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?

22. The
Electromagnetic
Spectrum

24. Table showing the EM waves’ wavelengths,
frequencies, and energies

25. 1.Radio waves
- have the longest wavelength
- produced by making electrons
vibrate in an antenna.
- used to transmit sound and
picture information over long
distances.

26. 2.Microwaves
- have smaller wavelengths than
radio waves
- can penetrate the atmosphere of
the Earth
- used in satellite
communication,radar,television
transmission and cooking

27. 3.Infrared waves
- lies beyond the red end of the
visible light.
- it is emitted by all objects.The
amount and wavelength of
radiation depend on temperature.
Below 500 C
ͦ , an object emits only
infrared radiation. Above 500 C, an
ͦ
object glows and emits both infrared
and some visible light.

28. 4.Visible Light
- When white light passes through a
prism , it is separated into its
constituent colors:
- These colors do not distinctly separate
but they continuously change from red to
violet. Red has the longest wavelength
from among these colors and violet has the
shortest.
R O Y G B I V

30. 5.Ultraviolet radiation
- lies just beyond the violet end of
the visible spectrum.
- have shorter wavelengths than the
visible light and carry more
energy.
- the SUN is the main source of UV
radiation but there are also
artificial sources of UV light.

31. 6.X - rays
- come just after the UV rays.
- they are of shorter wavelength but
carries higher energy than the UV.
- X-rays are produced using an X-
ray tube.They are emitted when
fast moving electrons hit a metal
target.

32. 7.Gamma rays
- lie at the other end of the EM
spectrum.
- they are shortest in wavelength
and highest in frequency.
- they carry the highest amount of
energy,thus they are more
dangerous.
- emitted by stars and some
radioactive substances.