English

Answer the Following Question. Why a Signal Transmitted from a Tv Tower Cannot Be Received Beyond a Certain Distance? Write the Expression for the Optimum Separation Between the Receiving - Physics

Advertisements
Advertisements

Question

Answer the following question.
Why a signal transmitted from a TV tower cannot be received beyond a certain distance? Write the expression for the optimum separation between the receiving and the transmitting antenna.

Short Note

Solution

The signal transmitted from a TV tower cannot be received beyond a certain distance because of the curvature of the earth. The expression for the optimum separation between the receiving and transmitting antenna:

`d = sqrt(2hR)`

d: Optimum separation.
h: Height of the antenna  
R - Radius of the curvature of Earth. 

shaalaa.com
  Is there an error in this question or solution?
2018-2019 (March) 55/1/3

RELATED QUESTIONS

Define modulation index.


Draw a sketch of a sinusoidal carrier wave along with a modulating signal and show how these are superimposed to obtain the resultant amplitude modulated wave


Due to economic reasons, only the upper sideband of an AM wave is transmitted, but at the receiving station, there is a facility for generating the carrier. Show that if a device is available which can multiply two signals, then it is possible to recover the modulating signal at the receiver station.


What is the role of a bandpass filter?


The carrier wave of a signal is given by C(t) = 3 sin (8πt) volt. The modulating signal is a square wave as shown. Find its modulation index.


Given modulation index physical significance .For an amplitude modulated wave, the maximum amplitude is found to be 10 V while the minimum amplitude is 2 V. Determine the modulation index μ ?


A 100 m long antenna is mounted on a 500 m tall building. The complex can become a transmission tower for waves with λ.


I-V characteristics of four devices are shown in Figures.

(i) (ii) (iii) (iv)

Identify devices that can be used for modulation.


An audio signal of 15kHz frequency cannot be transmitted over long distances without modulation because ______.

  1. the size of the required antenna would be at least 5 km which is not convenient.
  2. the audio signal can not be transmitted through sky waves.
  3. the size of the required antenna would be at least 20 km, which is not convenient.
  4. effective power transmitted would be very low, if the size of the antenna is less than 5 km.

A carrier wave Vc(t) = 160 sin(2π × 106t) volts is made to vary between Vmax = 200 V and Vmin = 120 V by a message signal Vm(t) = Am sin(2π × 103t) volts. The peak voltage Am of the modulating signal is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×