Advertisements
Advertisements
Question
In the given block diagram of a receiver, identify the boxes labeled as X and Y and write their functions.
Advertisements
Solution
X → If stage → Intermediate frequency stage to change the carrier frequency to lower frequency.
Y → Amplifier → It amplifies the signal i.e. it increase the amplitude of the detected signal to compensate the attenuation of the signal. The detected signal may not be strong enough to use.
RELATED QUESTIONS
Define modulation index.
Explain the need for modulation related to the size of antenna (aerial).
Why is Modulation index kept low?
What is the role of a bandpass filter?
In a communication system, what is meant by modulation?
The carrier wave of a signal is given by C(t) = 3 sin (8πt) volt. The modulating signal is a square wave as shown. Find its modulation index.
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.
A speech signal of 3 kHz is used to modulate a carrier signal of frequency 1 MHz, using amplitude modulation. The frequencies of the sidebands will be ______.
I-V characteristics of four devices are shown in Figures.
 |
 |
 |
|
| (i) | (ii) | (iii) | (iv) |
Identify devices that can be used for modulation.
A transmitting antenna has a height of 320 m and that of receiving antenna is 2000 m. The maximum distance between them for satisfactory communication in line of sight mode is 'd'. The value of 'd' is ______ km.
