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

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

Identify the 'INCORRECT' statement from the following?

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

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

A carrier wave of peak voltage 16 volt is used to transmit a signal. If the modulation index is $75 \%$, the peak voltage of the modulating signal is

In the process of space communication, use of modem is necessary. In which one of the following modes modem acts as a modulator and a demodulator respectively?

In communication system, the range for line of sight propagation in case of earth is 'd', for the height of antenna (h). If 'h' is doubled then the new range is

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

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