Test: Introduction to Communication System - Electronics and Communication Engineering (ECE)

Very high frequency (VHF) has a frequency range of 30-300 MHz and wavelength range of 10 to 1 m.

Correct Answer :-D 

Explanation : A-4, B-3, C-1, D-2

a) Transmission channel, the path between two nodes of a network that a data communication follows. The term can refer to the physical cabling that connects the nodes on a network, the signal that is communicated over the pathway or a subchannel in a carrier frequency.

b) In telecommunications, a carrier wave, carrier signal, or just carrier, is a waveform that is modulated (modified) with an information bearing signal for the purpose of conveying information.

c) Modulation is a process by which a carrier signal is altered according to information in a message signal.

d)  Distortion is any undesired change in the amplitude or phase of any component of an information signal that causes a change in the overall waveform of the signal.

The communication medium is the channel through which the message travels from the transmitter to the receiver. During the process of transmission and reception the signal gets distorted due to noise introduced in the system.

The message from the information source may or may not be electrical in nature. In a case when the message produced by the information source is not electrical in nature, an input transducer is used to convert it into a time-varying electrical signal.

Communication is simply the basic process of exchanging information.

Correct Answer :- c

Explanation : In the communication process, a medium is a channel or system of communication—the means by which information (the message) is transmitted between a speaker or writer (the sender) and an audience (the receiver).

 Wire is not a major communication medium.

In a wired network, data is transmitted over a physical medium.

Nowadays, wireless networks are being used. So wired connection is not a major communication medium.

Multiplexing may be defined as the process of combining several message signals together and send them over the same communication channel, i.e. FDM, TDM and CDM.