Question

Which of the following is used for modulation and demodulation?
(A) Modem
(B) Protocols
(C) Gateway
(D) Multiplexer

Answer 1

Hint : We are nowadays able to transfer data over the internet with such high speed. This requires modulation and demodulation of data signal at both ends as the signal requires strength to travel.

Complete Step By Step Answer:
First of all, for a better approach to answer the above question let’s understand modulation and demodulation.
In electronics and communication systems, the information has to travel long distances so we use carrier waves of higher frequency to carry our data, thus modulation means varying some aspect of a continuous wave carrier signal with an information-bearing modulation waveform.
When this information bearing carrier wave reaches its destination we have to separate the two in order to retrieve the information and this is known as demodulation.
For understanding options, a gateway provides a single input and output whereas a multiplexer provides several inputs and one or more than one outputs.
We in our internet service setup, use a device called modem: a word which is made of abbreviation of ‘MOdulation' and ‘DEModulation. It is capable of doing both the tasks mentioned above.
Hence ‘A’ is the right answer.

Note :
It is worthy to note the difference between protocol and Modem, as protocol is the method of only arranging the data that is to be transmitted. Be clear with the properties and difference among the given terms.