Among the following which one is wrong for sky wave propagation? |
Sky waves are reflected back to the earth by ionosphere Sky waves are radio waves of frequency range 2 MHz to 30 MHz Sky wave propagation is used by short wave broadcast services Sky waves are radio waves of very high frequency 30 MHz to 300 MHz |
Sky waves are radio waves of very high frequency 30 MHz to 300 MHz |
The correct answer is option (4) : Sky waves are radio waves of very high frequency 30 MHz to 300 MHz Sky wave propagation, also known as ionospheric propagation is the mode of propagation in which electromagnetic waves from antenna are reflected back to earth by atmosphere. The permitted frequency ranges from 3MHz to 30 MHz. Short wave radio services use sky wave propagation. It is also used for satellite communication. Hence the fourth option is wrong. |