Communication System

Match Column A (layers in the ionosphere for skywave propagation) with Column B (their height range) $\begin{array}{llll}\mathrm{A} & \mathrm{B} & \mathrm{C} & \mathrm{D}\end{array}$

Three signals related to amplitude modulation are shown in the figure. The correct assignment of the signals is

The maximum distance between the transmitting and receiving TV towers is $65 \mathrm{~km}$. If the ratio of the heights of the TV transmitting tower to receiving tower is $36: 49$, the heights of the transmitting and…

Band width of an optical fiber is

If the length of an antenna is $150 \mathrm{~cm}$, the transmission frequency is ____ $\mathrm{MHz}$. (Speed of light in vacuum $=3 \times 10^8 \mathrm{~ms}^{-1}$)

The radio horizon of the transmission of an antenna placed on $20^{\text {th }}$ floor in a shopping mall, where the height of each floor is $2 \mathrm{~m}$ is (Radius of earth is $6.4 \times 10^6 \mathrm{~m}$)

The frequency suitable for beyond-the-horizon communication using sky waves is

A TV tower has a height of $150 \mathrm{~m}$. If the population density around the TV tower is $10^3 \mathrm{~km}^{-2}$ then the population covered by the tower is (Radius of the earth, $\mathrm{R}=6.4 \times 10^6…

The maximum amplitude of an amplitude modulated wave is $16 \mathrm{~V}$, while the minimum amplitude is $4 \mathrm{~V}$. The modulation index is

A TV transmitter has a range of $50 \mathrm{~km}$. The height of the TV transmitter is _________ (Radius of the earth, $R_e=6 \cdot 4 \times \overline{10^6 \mathrm{~m} \text {) }}$

A transmitting antenna of height $20 \mathrm{~m}$ and the receiving antenna of height $h$ are separated by a distance of $40 \mathrm{~km}$ for satisfactory communication in line of sight (Los) mode. Then the value of…

The process of increasing the strength of a signal using an electronic circuit is called