Communication System Physics - Communication System

The device which works of both modulation and demodulation is called :

Distance of communication satellite from the surface of the earth :

Attenuation is measured in :

Meaning of "FAX" is :

The height of a T.V. transmission tower at any place on the surface of the earth is 245 m. The maximum distance upto which transmission of tower will reach is :

A carrier wave of peak voltage 15 V is used to transmit a message signal. Find the peak voltage of the modulating signal in order to have a modulation of 60%.

Explain www and Fax.

Explain frequency modulation.

State two factors by which the range of transmission of T.V. signal can be increased.

Write the principle of MODEM in brief.

Explain the following:
(a) Ground Waves, (b) Sky Waves, (c) Space Waves.

What is Remote Sensing ? Mention two of its applications.

What is amplitude modulation ? Draw the simple block diagram of a modulator to get amplitude modulated wave.

Explain the terms: (i) Attenuation, (ii) Demodulation used in communication system.

Explain LOS mode of communication.

Draw a block diagram of a generalized communication system. Write the functions of each of the following:
(a) Transmitter, (b) Channel, (c) Receiver.

What are signals ? What do you mean by analog and digital signals ?

In how many bands the full range of radiowaves can be divided ? Describe about all the bands in brief.

What are different kinds of modulation ? Explain.

(i) Which mode of propagation is used by short wave broadcast services having frequency range from a few MHz to 30 MHz? Explain diagrammatically how long distance communication can be achieved by this mode.
(ii) Why is there an upper limit to frequency of waves used in this mode ?

Write the need of modulation in communication system.

(A) Explain the follwing :
(i) E-mail, (ii) File transfer, (iii) WWW, (iv) Fax, (v) E-commerce, (vi) Instant Relay Chat (IRC).
(B) What is co-axial cable ? State its uses.