06-10-2012, 05:08 PM
Technology for communicating information
5170566-Communication-Technology.pdf (Size: 345.51 KB / Downloads: 26)
How do we communicate?
We all use different methods at different times to communicate. We can
communicate by making
gestures with parts of our body,
for example shaking of our head
or hands, winking, making faces
etc. We also communicate by
speaking or making sounds like
laughing, weeping or sobbing. At
a more advanced level we
communicate by writing and
reading. At this moment the
author is communicating to you
through the text and pictures
printed on the pages of this book.
But, there is yet another way we can communicate. That is by using
electrical gadgets, invented by scientists and technologists, for example,
radio, telephone, television and computers. For such communication
electromagnetic waves come handy.
What are electromagnetic waves?
Electromagnetic waves are a kind of waves that pervade the universe.
They are so called because they often originate due to interaction of electric
charges and magnets. Light is also an electromagnetic wave.
In 1831, a British scientist Michael Faraday discovered that changing
electric current in a coil of wire induces a current in a nearby coil.
Do animals talk?
Animals make a wide variety of sounds,
from the musical song of a bird to the howl
of the wolf, to the contented purr of a cat.
While they are unable to talk in the sense
that humans do, they do communicate with
sound in a way that is understood only by
other members of their own species. Still, we have been unable to translate
individual animal sounds in a framework that can be called true language.
What is RAM?
When we sit for an examination in school, we often cram up many facts so
that we can remember them rapidly when we need them. We often forget
these facts and instructions once the examination is over. The kind of
memory we use for this purpose is known as the short-term memory. In a
computer also there is a short-term memory; it is called RAM (Random