Question

AM is used for broadcasting because
A. It is more noise immune than other modulating systems
B. It requires less transmitting power compared to other systems.
C. Its use avoid complexity
D. No other modulation system can provide the necessary bandwidth and faithful transmission

Answer 1

Amplitude modulation or AM one a technique used to transmit data by modifying the carrier signals. We use modulations to send information to long distances since we can’t use low frequency signals to cover large areas. To find the reason for using amplitude modulation in broadcasting, let us consider all the four cases given and compare it with other modulations.

Complete step by step answer:
AM or amplitude modulation is a technique used to modulate a wave by varying its amplitude.
We are asked the reason why amplitude modulation technique is used for broadcasting.
We are given four cases in the question.
Let us consider the first case.
It is said that we use AM because it is more noise immune than other modulating systems.
This is wrong. Because if we consider frequency modulation (FM), we know that it is much noise immune when compared to amplitude modulation.
Hence this case is wrong.
Let us consider the second case.
In this case it is said that we use AM because, Am requires less transmitting power when compared to other modulating systems.
Let us again compare it with frequency modulation. We know that FM requires less power for transmitting when compared to AM.
Hence this case is also wrong.
In the third case it is said that the use of amplitude modulation avoids complexity.
We know that the circuit of amplitude modulation is simple when compared with the circuit of other modulations like frequency modulation. Frequency Modulation has a very complex circuit.
Since amplitude modulation has a simple circuit, the use of AM avoids complexity.
Hence this case is right.
Now let us consider the fourth case.
In this case it is said that AM provides necessary bandwidths and faithful transmission.
The transmission of AM is not faithful because AM can be controlled digitally.
Hence this case is also wrong.
Therefore the only right case is that amplitude modulation has a very simple circuit and hence the use of it reduced the complexity.

Hence the correct answer is option C.
The circuit used for amplitude modulation is very simple.

Note:
Amplitude modulation (AM) and frequency modulation (FM) are two techniques used for modulation,
In amplitude modulation, the wave is modified by varying the amplitude of the wave and keeping the wave’s frequency constant.