Communication Systems

A radar has a power of $1kW$ and is operating at a frequency of $10$ $GHz.$ It is located on a mountain top of height $500$ $m.$ The maximum distance upto which it can detect object located on the surface of the earth (Radius of earth $= 6.4 \times {10^6}m$) is :

A signal is to be transmitted through a wave of wavelength $\lambda$, using a linear antenna. The length l of the antenna and effective power radiated P_eff will be given respectively as : (K is a constant of proportionality)

A telephonic communication service is working at carrier frequency of 10 GHz. Only 10% of it is utilized for transmission. How many telephonic channels can be transmitted simultaneously if each channel requires a bandwidth of 5 kHz ?

In a communication system operating at wavelength 800 nm, only one percent of source frequency is available as signal bandwith. The number of channels accomodated for transmitting TV signals of band width 6 MHz are (Take velocity of light c = 3 $\times$ 10⁸m/s, h = 6.6 $\times$ 10^$-$34 J-s)

A TV transmission tower has a height of 140 m and the height of the receiving antenna is 40 m. What is the maximum distance upto which signals can be broadcasted from this tower is LOS (Line of Sight) mode ? (Given : radius of earth = 6.4 × 10⁶ m).

To double the covering range of a TV transmittion tower, its height should be multiplied by :

The wavelength of the carrier waves in a modern optical fiber communication network is close to :

In a line of sight radio communication, a distance of about 50 km is kept between the transmitting and receiving antennas. If the height of the receiving antenna is 70m, then the minimum height of the transmitting antenna should be : (Radius of the Earth = 6.4 × 10⁶ m).

The physical sizes of the transmitter and receiver antenna in a communication system are :-

Given below in the the left column are different modes of communication using the kinds of waves given the right column. .tg {border-collapse:collapse;border-spacing:0;width: 100%} .tg td{font-family:Arial, sans-serif;font-size:14px;padding:10px 5px;border-style:solid;border-width:1px;overflow:hidden;word-break:normal;border-color:black;} .tg th{font-family:Arial, sans-serif;font-size:14px;font-weight:normal;padding:10px 5px;border-style:solid;border-width:1px;overflow:hidden;word-break:normal;border-color:black;} .tg .tg-hgcj{font-weight:bold;text-align:center} .tg .tg-s268{text-align:left} .tg .tg-xk68{font-weight:bold;color:#fe0000;text-align:center} .tg .tg-0lax{text-align:left;vertical-align:top} A Optical Fibre communication P Ultrasound B Radar Q Infrared Light C Sonar R Microwaves D Mobile Phones S Radio Waves