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2. Telephones
Before there were any telephones invented, people used to send long
letters which was very tiring. Now people use phones which can be
taken anywhere. Now it is so technological that most people have
I-phones, laptops etc.
3. Who created the telephone??
Alexander Graham bell created the first successful telephone in the
world. He was Scottish-born inventor, scientist, and teacher who
was widely credited as the inventor of the electric telephone. On
March 7th 1876 he became the first to receive a patent for this
device.
4. More about his life
While he was creating a telephone, at the same time he began
working at the idea that speech could be transmitted
electronically, as he accidentally discovered that the sound of a
spring being twanged could be heard over his harmonic telegraph
system. Almost a year later in March 1876 Bell uttered the first
famous words into the device to his assistant in the next
room.
5. More about telephones..
Call signals to places close by travel along wires or cables buried
underground .But when the person you call is very far away, the
electrical signals sent from your phone are changed into invisible
waves of energy called microwaves, which travel long distances
through the air. These waves are send to space and its connected to
satellite and then bounces back to earth. An antenna at a receiving
station near the home of your friend picks up the waves and changes
them to electrical signals once more. They travel by cable to the
telephone office that services your friend's neighborhood, where
his or her number is identified. The signal rings, your friend
picks it up. There is a microphone connected her telephone, and
then you hear it in seconds.
6. How do telephones work?
When you pick up a phone, a low electrical current allows you to
dial the series of numbers that will connect you to the phone of a
friend, for example. A local telephone office receives this
information when you dial and sends your call in the right
direction.
7. Credits:
http://www.answers.com/topic/how-do-telephones-work
Presented By Bhumika Y6h
My L.O:to know who created telephone and how it works
8. Pictures of different telephones