ppt is about electromagnetic waves and their uses in various fields of work

2. INDEX
S.NO. TITLE
1. Acknowledgement
2. Certificate
3. Introduction
4. Electromagnetic spectrum
5. Types of EM waves
6. Uses of EM waves
7. Conclusion
8. Bibliography

3. INTRODUCTION
Electromagnetic waves:
The waves that are propagated by simultaneous periodic
variations of electric and magnetic field intensity and that
include radio waves, infrared, visible light, ultraviolet, X-
rays, and gamma rays are knoown as EM waves.
Transmission of energy through a vacuum or using no
medium is accomplished by electromagnetic waves,
caused by the osscilation of electric and magnetic fields.
They move at a constant speed of 3x108 m/s.
Electromagnetic waves are used to transmit
long/short/FM wavelength radio waves, and
TV/telephone/wireless signals or energies. They are also
responsible for transmiting energy in the form of
microwaves, infrared radiation (IR), visible light ,ultraviolet
light (UV), X-rays, and gamma rays.

6. 1. Gamma rays
2. X – rays
3. Ultraviolet
4. Visible light
5. Infra-red
6. Microwaves
7. Radio waves

7. (1) Gamma rays
USES
1. It is used for treatment of cancerous cell in our
body without the use of the surgery.
2. It is used in industries to kill the harmful
bacteria, organism like yeast etc.
3. It is also used to sterilize medical instruments.
4. It is used to detect brain and heart
abnormalities.
5. Gamma rays are used by Engineers, since they
can penetrate better than X-rays, to look for
cracks in pipes and aircraft parts..
6. One of the destructive use is their important role
in development of the atomic bomb.

8. (2) X-rays
USES
1.In art: detecting covered paintings
2.In engineering: checking metal castings
for defects or to check flaws in bridges
3.In medicine: there are two main areas
(a) diagnostic-The detection of a broken
bone,a tooth cavity,tuberclosis of lungs,
presence of stones in gall bladder and
kidney
(b) therapeutic- The treatment of
malignant cancers
4. In physics: used to study crystal structure

9. (3) Ultraviolet rays
USES
1. UV rays provide vitamin D.
2.They are used to sterilise drinking water and
surgical instruments.
3.They are used to detect invisible writing,forged
documents,finger prints etc in forensic labs.
4. Ultraviolet energy which makes them excellent
for sanitizing the air and killing germs and
bacteria. They also get rid of molds, mildews,
fungi and many kinds of viruses.
5.In the dairy industry, UV disinfection is used
especially for the packaging of fresh milk
products, which are kept in the cool chain, in order
to improve shelf life.

10. (4) Visible light
USES
1.Visible light is extremely important to humans,
we use it TO SEE! Without light, our eyes
would not be able to see images of anything.
2.We concentrate visible light to make lasers to
use in everything from surgery, to CD players to
laser pointers.
3.Visible light waves also make our TV,
computer and cell phone screens work.

11. (5) Infra-red waves
USES
1.The most common use of infrared in everyday
life is remote controls. These work by sending
pulses of infrared that spell out a message to an
electronic device.
2.Thermal imaging cameras use infrared to look at
human body heat emissions, both for medical
purposes and in night-vision cameras.
3.Toasters, ovens and heat lamps all work
because of infrared waves.
4.Infrared is often used to send signals through
fiber optic cables, particularly when using standard
silica fibers.
5.Infrared is also widely used in astronomy. Taking
pictures of the universe in infrared can lead to
some amazing discoveries.

12. (6) Microwaves
USES
1.Microwaves cause water molecules to vibrate
more quickly and, therefore, heat up.That's how in
microwave ovens work.
2.Microwaves are also used by fixed traffic speed
cameras, and for radar, which is used by aircraft,
ships and weather forcasters.
3.Microwaves are also used to send messages
from our cell phones.
4.Microwaves are primarily used in medical cases
as an alternative to surgery.
5.They can be used to decrease air pollutants,
sanitize hospital waste, enhance dry cleaning
solvents, and clean up polluted soil.

13. (7) Radiowaves
USES
1. They are mainly used for communications
2.Aside from transmitting music from radio
stations, radio waves are used by the military,
airports, and by safety officers to relay
information.
3.Each organization uses different frequencies
of waves to avoid confusing messages,like in
FM radio.
4.Even astronauts can use radio waves while
they are in outer space to communicate with
each other and with NASA back on Earth.

14. As we know by now, electromagnetic waves are
used in every field of work everyday.EM waves has
helped world immensely to develop.Without usage
of them we can't even live properly.
Over-exposure to certain types of electromagnetic
radiation can be harmful. The higher the frequency
of the radiation, the more damage it is likely to
cause to the body:
• microwaves cause internal heating of body
tissues
• infrared radiation is felt as heat and causes skin
burns
• X-rays damage cells, causing mutations (which
may lead to cancer) and cell death
• gamma rays also damage cells, causing
mutations (which may lead to cancer) and cell
death

15. • www.scienceclarified.com
• www.sites.google.com
• www.darvill.clara.net
• www.study.com