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प्रश्न
In a communication system, what is meant by modulation?
उत्तर
Superimposition of low-frequency message signal on high-frequency carrier wave called modulation.
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संबंधित प्रश्न
Define modulation index.
The carrier wave is given by
C(t) = 2sin(8πt) volt.
The modulating signal is a square wave as shown. Find modulation index.
Explain the need for modulation related to the size of antenna (aerial).
Answer the following question.
Why a signal transmitted from a TV tower cannot be received beyond a certain distance? Write the expression for the optimum separation between the receiving and the transmitting antenna.
Broadcasting antennas are generally ______.
A 100 m long antenna is mounted on a 500 m tall building. The complex can become a transmission tower for waves with λ.
A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to ______.
A TV transmission tower antenna is at a height of 20 m. How much service area can it cover if the receiving antenna is (i) at ground level, (ii) at a height of 25 m? Calculate the percentage increase in area covered in case (ii) relative to case (i).
A 25 m long antenna is mounted on an antenna tower. The height of the antenna tower is 75 m. The wavelength (in meter) of the signal transmitted by this antenna would be ______.
A carrier wave Vc(t) = 160 sin(2π × 106t) volts is made to vary between Vmax = 200 V and Vmin = 120 V by a message signal Vm(t) = Am sin(2π × 103t) volts. The peak voltage Am of the modulating signal is ______.
