Communication System

In communication system, for a given block diagram of receiver, the boxes ' $\mathrm{X}$ ' and "Y' respectively represent

In frequency modulated wave

In commmunication system, a repeater is used to extend the range of transmission. It is the combination of

In communication system, what is used to extend the range of a communication?

According to theoretical study of radiation from a same linear antenna, the power radiated is proportional to $[\lambda=$ wavelength $]$

The digital signals are used for transmission in communication system. They are

Which of the following is the communication channel in case of radio communication?

A layer of atmosphere that reflects medium frequency radio waves which is ineffective during night, is

In communication system the process of superimposing a low frequency signal on a high frequency wave is known as

A signal of frequency $3 \mathrm{kHz}$ is amplitude modulated on a carrier wave of frequency $2 \cdot 5 \mathrm{MHz}$. The upper and lower sideband frequencies in the resultant signal are

In amplitude modulation, the amplitude of carrier wave is $A_{c}$ and that of the modulating signal is $A_{m}.$ In practice, the ratio of $A_{m}$ to $A_{c}$ is kept less than or equal to one, to avoid

In amplitude modulation