2. FLOW OF INFORMATION

3. INFORMATION
• Arranged form of data
which is communicated
or received and has a
particular meaning.

4. FLOW OF INFORMATION
Flow of
information
means transfer of
information from
one place to
another through
different
electronic and
optical
equipment.

5. EXAMPLES
In telephones,
information is
sent through
wires in the
form of
electrical
signals.

6. • In radio,
television and
cell phone
information is
sent either
through space
in the form of
electromagnetic
waves, or
through optical
fibres in the
form of light.

9. ELEMENTS OF A
COMMUNICATION
SYSTEM
There are three essential parts of a
communication system:
Transmitter
Transmission channel
Receiver

10. TRANSMITTER
TRANSMISSION
CHANNEL
RECEIEVER
INPUT
SIGNAL
TRANSMMITED
SIGNAL
RECEIVED SIGNAL
DESTINATION
OUTPUT SIGNAL

11. Transmitter
A set of equipment used to generate and
transmit electromagnetic waves carrying
messages or signals, especially those of radio
or television.

12. Transmission channel
A path between two nodes in a network.
It may refer to the physical cable, the
signal transmitted within the cable

13. Receiver
A person or device that gets or accepts
something that has been sent or given to
them.

14. WORKING OF A
COMMUNICATION
SYSTEM
The transmitter processes the input signal. The
transmission channel is the medium which sends the
signal from source to destination. It may be a pair of
wires, a coaxial cable, a radiowave or optical fibre
cable. So, the signal power progressively decreases
with increasing distance.

15. The receiver takes the output signal from the
transmission channel and delivers and
delievers it to the transducer after processing
it. The receiver may amplify the input signal
to compensate for transmission loss.

16. TRANSMISSION OF ELECTRICAL
SIGNALS THROUGH WIRES

17. Introduction to telephone
• Alexander Graham Bell in 1876 made a simple
telephone model to send voice in the form of
electrical signal from one place to another.

18. Simple telephone
consists of :
•Metal reed
•Electric coil
•Vibrating diaphragm
Modern telephone also
uses :
•Mouth piece
•Ear piece
•Vibrating diaghram

19. When we speak into the mouthpeice the sound
vibrations also vibrate the diaphragm . A slight
vibration of thecdiaphragm compresses the
carbon granules present in it and thus an
electric current can flow through the wire.
How does it
work???

20. This process is reversed at the other end of the line
by the receiver. The electrical current flowing
through an electromagnet in the receiver produces
a varying magnetic field. This magnetic field
attracts the thin metal diaphragm in the receiver,
causing it to vibrate. This vibration of the
diaphragm produces sound waves.

23. Thank you :,)