NCERT Solutions for Chapter: Communication Systems, Exercise 1: MCQ

A $100 \mathrm{m}$ long antenna is mounted on a $500 \mathrm{m}$ tall building. The complex can become a transmission tower for waves with $\mathrm{\lambda }$

A $1 \mathrm{KW}$ signal is transmitted using a communication channel which provides attenuation at the rate of $– 2\mathrm{dB} \mathrm{per} \mathrm{km}$.If the communication channel has a total length of $5 \mathrm{km}$, the power of the signal received is 

A speech signal of $3 \mathrm{kHz}$ is used to modulate a carrier signal of frequency $1 \mathrm{MHz}$, using amplitude modulation. The frequencies of the side bands will be

A message signal of frequency ${\mathrm{\omega }}_{\mathrm{m}}$ is superposed on a carrier wave of frequency ${\mathrm{\omega }}_{\mathrm{c}}$ to get an amplitude modulated wave $\left(\mathrm{AM}\right)$.The frequency of the $\mathrm{AM}$ wave will be

$\mathrm{I}-\mathrm{V}$ characteristics of four devices are shown in figure

Identify devices that can be used for modulation:

A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to

A basic communication system consists of

(A) transmitter.

(B) information source.

(C) user of information.

(D) channel.

(E) receiver.

Choose the correct sequence.

Identify the mathematical expression for amplitude modulated wave: