Page 158 - Physics 10_Float

INFORMATION TECHNOLOGY

5. People: Every CBIS needs people if it is to be useful, who For your information
influence the success or failure of information systems.
People design and operate the software, they feed input
Insulating
data, build the hardware for the smooth running of any CBIS. sleeve
People write the procedures and it is ultimately people who
determine the success or failure of a CBIS.

17.3 FLOW OF INFORMATION
Cylindrical braid
Flow of information means the transfer of information from one Solid wire
place to another through different electronic and optical Coaxial cable wires are used to
equipments. In telephone, information is sent through wires in transmit electric signals such
the form of electrical signals. In radio, television and cell phone as cable TV to our homes. To
prevent electric and magnetic
information is sent either through space in the form of interference from outside, a
electromagnet waves, or through optical fibres in the form of covering of conducting
light. Radiowaves are continuously refracted by different layers material surrounds the coaxial
in the Earth's atmosphere. This leads to weaken the signal, wires.
making it difficult to be received over long distances. Unlike
radiowaves, microwaves are not refracted. They are used for
satellite communication.
Fig. 17.2 shows the elements of a communication system.
There are three essential parts of any communication
system: transmitter, transmission channel, and receiver.

Input Transmitted Received Output
signal signal signal signal
Transmission
Receiver
Transmitter channel Receiver Destination

Noise, interference
and distortion

Fig. 17.2
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 radio-
wave or optical fibre cable. So, the signal power progressively
decreases with increasing distance. The receiver takes the
output signal from the transmission channel and delivers it to
the transducer after processing it. The receiver may amplify
the input signal to compensate for transmission loss.

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