Please wait...
1800-212-7858 (Toll Free)
9:00am - 8:00pm IST all days

or

Thanks, You will receive a call shortly.
Customer Support

You are very important to us

For any content/service related issues please contact on this toll free number

022-62211530

Mon to Sat - 11 AM to 8 PM

what is the need for modulation?
what are sky waves , space waves and ground waves?
 

Asked by gsonu953 3rd March 2015, 10:32 AM
Answered by Expert
Answer:
Modulation needs to be done because:
 
1) The size of antenna should be of the size comparable to the wavelength of the signal. the signal wavelength is very large so large antenna is not possible to construct.
2) The effective power radiated by an antenna decreases with increase in wavelength.
3) There is mixing up of signals due to multiple transmitters.
 
Sky waves: Long distance communication is achieved by ionospheric reflection of radio waves. These waves are called sky waves and the mode of propagation is called sky wave propagation.
 
Space waves: A space wave travels in a straight line from transmitting antenna to the recieving station. They are used for line-of-sight paths.
 
Ground waves: For standard AM braodcast, the ground based vertical towers are used as transmitting antennas. The waves sent by these antennas are called surface waves or ground waves.
Answered by Expert 3rd March 2015, 7:53 PM
Rate this answer
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10

You have rated this answer /10

Your answer has been posted successfully!

Latest Questions

ICSE IX History and Civics
Asked by lovedewangan9 20th June 2018, 11:52 PM

Chat with us on WhatsApp