Umakant Kondapure, Collin Fernandes, Nipun Bhatia, Vikram Bathula and, Ketki Deshpande Solutions for Chapter: Communication Systems, Exercise 2: Critical Thinking

The maximum line-of-sight distance $d_M$ between two antennas having height $h_T$ and $h_R$  above the earth is

A transmitting antenna at the top of a tower has a height of $50 \mathrm{m}$ and the height of the receiving antenna is $32 \mathrm{m}$. What is the maximum distance between them for satisfactory communication in line of sight rnode?

When an electromagnetic wave enters the ionised layer of ionosphere, the motion of electron cloud produces a space current and the electric field has its own capacitative displacement current, then

For the first pair of side band frequencies, band width required for amplitude modulation is

In FM, frequency deviation is

Consider an optical communication system operating at $\lambda \sim 800 \mathrm{nm} .$ Suppose only $1 \%$ of the optical source frequency is the available channel bandwidth for optical communication. How many channels can be accommodated for transmitting audio signals requiring a bandwidth of $8 \mathrm{kHz}$ ?

(Speed of light$=3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-2}$)

A telephone link is operating at a central frequency of $10 \mathrm{GHz}$. If $1 \%$ of this is available then how many telephone channels can be simultaneously given when each telephone covers a band width of $5 \mathrm{kHz}$ ?

Assertion: FM broadcast is preferred over AM broadcast.

Reason: The process of combining the message signals with carrier-wave is called demodulation.