Elements of a Communication System

A device used for transmission of images scanned at a transmitting point and duplicated at a receiving point is

A device mounted on a communication satellite which receives, amplifies and retransmits signals' from earth stations is called

A message signal of 12 kHz and peak voltage 20 V is used to modulate a carrier wave of frequency 12 MHz and peak voltage 30 V. Calculate the (i) modulation index (ii) side-band frequencies.

What should be the length of dipole antenna for a carrier wave of frequency $5\times {10}^8\mathrm{Hz}$ ?

What should be the length of dipole antenna for a carrier wave of frequency $6\times {10}^{8}H\text{z}$ ?

The length of a dipole antenna for a carrier wave of frequency $6\times {10}^8\text{Hz}$ is ( take speed of EM wave $3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$ )

A transmitting antenna at the top of a hill has a height $72 \mathrm{m}$ and the height of the receiving antenna is $128 \mathrm{m}$. The maximum distance between them for satisfactory communication in LOS mode is

(Use Radius of earth $=6.4\times {10}^6 \mathrm{m}$)

What is used for Ring Modulator?

 In TV transmission, sound signal is _____ modulated.

In TV transmission, picture signal is _____ modulated.

Modulation is done in _____.

Which type is used and preferred in digital logic circuits?

Examples of PCM waveforms are

 When pulse code modulation is applied to non-binary symbols we obtain waveform called as.

 AVC stands for _____

Ring Modulator is _____.

Square Law modulators are _____

 Modulation is done in _____

Find the length of transmitting antenna, if a carrier wave of $1000 \mathrm{kHz}$ is used to carry the signal.

The process of superimposing a signal frequency on the carrier wave is known as