At which of the following frequency/ frequencies the communication will not be reliable for a receiver situated beyond horizon :
(a) 10 kHz (b) 10 MHz
(c) 1 GHz (d) 1000 GHz
Digital signals (i) do not provide a continuous set of values, (ii) represent values as discrete steps, (iii) can utilize only binary system, and (iv) can utilize decimal as well as binary system. Which of the following options is true :
(a) Only (i) and (ii).
(b) Only (ii) and (iii).
(c) Only (i), (ii) and (iii), but not (iv).
(d) All the above (i) to (iv).
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 81 m tall. How much service area can it cover if the receiving antenna is at the ground level ?
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% ?
A modulation
signal is a square wave as shown in figure. The carrier wave is given by
(i) Sketch the amplitude modulated waveform.
(ii) What is the
modulation index ?
For an amplitude
modulated wave, the maximum amplitude is found to be 10 V while the minimum
amplitude is found to be 2 V. Determine the modulation index
What would be the
value of if the minimum
amplitude is zero V ?