Q2 of 8 Page 530

Frequencies in the UHF range normally propagate by means of:

The signals having Ultra High Frequency(UHF) can propagate through Space waves. These can neither travel along the trajectory of ground as shown in green nor can propagate by reflection in the ionosphere as shown in figure in red. The UHF signal propagates as shown in Blue in the figure.

More from this chapter

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1

Which of the following frequencies will be suitable for beyond-the horizon communication using sky waves?

 3

Digital signals

(i) do not provide a continuous set of values,


(ii) represent values as discrete steps,


(iii) can utilize binary system, and


(iv) can utilize decimal as well as binary systems.


Which of the above statements are true?

 4

Is it necessary for a transmitting antenna to be at the same height as 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?

 5

A carrier wave of peak voltage 12V 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%?