English

The Process of Superimposing a Low Frequency Signal on a High Frequency Wave is

Advertisements
Advertisements

Question

The process of superimposing a low frequency signal on a high frequency wave is_______ .

Options

  • detection  

  • mixing

  • modulation 

  • attenuation

MCQ
Advertisements

Solution

modulation

The process of superimposing a low frequency signal on a high frequency wave is known as modulation.

shaalaa.com
  Is there an error in this question or solution?
2015-2016 (March)

APPEARS IN

RELATED QUESTIONS

Define modulation index.


State three important factors showing the need for translating a low frequency signal into a high frequency wave before transmission


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


How are side bands produced?


The carrier wave is given by

C(t) = 2sin(8πt) volt.

The modulating signal is a square wave as shown. Find modulation index.

 


A carrier wave of peak voltage 12 V is used to transmit a message signal. What should be the peak voltage of the modulating signal in order to have a modulation index of 75%?


Explain the need for modulation related to the size of antenna (aerial).


Why is Modulation index kept low?


State any two types of modulation


Define the term modulation. Draw a block diagram of a simple modulator for obtaining AM signal ?


In the given block diagram of a receiver, identify the boxes labeled as X and Y and write their functions.


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 ?


Broadcasting antennas are generally ______.


A speech signal of 3 kHz is used to modulate a carrier signal of frequency 1 MHz, using amplitude modulation. The frequencies of the sidebands will be ______.


A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to ______.


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 TV transmission tower antenna is at a height of 20 m. How much service area can it cover if the receiving antenna is (i) at ground level, (ii) at a height of 25 m? Calculate the percentage increase in area covered in case (ii) relative to case (i).


A 25 m long antenna is mounted on an antenna tower. The height of the antenna tower is 75 m. The wavelength (in meter) of the signal transmitted by this antenna would be ______.


A transmitting antenna has a height of 320 m and that of receiving antenna is 2000 m. The maximum distance between them for satisfactory communication in line of sight mode is 'd'. The value of 'd' is ______ km.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×