Exercise : Solutions of Questions on Page Number : 530
Which of the following frequencies will be suitable for
beyond-the-horizon communication using sky
Forbeyond-the-horizon communication, it is
necessary for the signal waves to travel a large distance. 10 KHz
signals cannot be radiated efficiently because of the antenna
size. The high energy signal waves (1GHz
- 1000 GHz)
penetrate the ionosphere. 10 MHz frequencies get reflected easily
from the ionosphere. Hence, signal waves of such frequencies are
suitable for beyond-the-horizon communication.
Frequencies in the UHF range normally propagate by means of:
Owing to its high frequency, an ultra high frequency
(UHF)wave can neither travel along the trajectory of
the ground nor can it get reflected by the ionosphere. The
signals having UHF are propagated through line-of-sight
communication, which is nothing but space wave
Is it necessary for a transmitting antenna to be at the
same heightas that of the receiving antenna for
line-of-sight communication? A TV transmitting antenna is 81m
tall. How much service area can it cover if the receiving antenna
is at the ground level?
For an amplitude modulated wave, the maximum
amplitudeis found to be 10 V while the minimum
amplitude is found to be 2 V. Determine the modulation
would be the value ofÃŽÂ¼if the
minimum amplitude is zero volt?
Physics Part 2 - Physics : CBSE NCERT Exercise Solutions for Class 12th for Communication Systems will be available online in PDF book form soon. The solutions are absolutely Free. Soon you will be able to download the solutions.