NCERT Solutions for Class 12 Physics Chapter 15 – Communication Systems

NCERT Solutions for Class 12 Physics Chapter 15 – Communication System contain all the core concepts that have been tackled in the chapter. These solutions assist you in ensuring your thorough preparations for your exams by practising all these questions which are included in the chapter. The chapter of NCERT Solutions for Class 12 Physics includes various fundamentals which are directly and indirectly used in solving all the questions from the exercise. 

Chapter 15 – Communication Systems comprises a total of one exercise and 8 questions which are all diverse in nature. All of these questions are based on the fundamentals of the chapter and revolve around the major concepts which have been portrayed through charts, graphs, theory, diagrams, examples and formulas in the chapter. The exercise includes short answer questions, reasoning questions, descriptive questions and some very basic one-word answers as well.

NCERT Solutions for Chapter 15 – Communication Systems will provide you with a simplified way of learning. The exercises cover all the nooks and corners of the chapter and ensure that you develop a firm command on the basics of the chapter through thorough practice. Instasolv’s NCERT Solutions for Class 12 Physics Chapter 15 – Communication Systems, have been carefully organized by a team of experienced individuals who understand your learning requirements. We aim at providing a stress-free and productive experience which will enable you to perform better and score well in your CBSE exams.

Important Topics covered in NCERT Solutions for Class 12 Physics Chapter 15 – Communication Systems

Communication System 

As the name suggests, the chapter deals with the communication system in a detailed manner and discusses its importance, features, characteristics and components. The terms which you will learn in the course of this chapter are –

Transducer – this device is used for the conversion of one form of energy to another. In case of the daily used devices, a transducer converts physical variables like pressure, force, temperature etc. into corresponding variations in the electric signal in the form of its output. 

Signal – when the information is converted in an electrical form and becomes suitable for transmission, it is termed as a signal. It is not necessary for a signal to only be in a digital format, it can also exist as an analog. 

Noise – the unwanted signals which cause disturbance to the transmission and the processing of message signals are known as noises. 

Transmitter – a transmitter does the processing of the incoming message signal and makes it suitable for transmission through a channel and a reception. 

Receiver – A receiver does the job of extracting the message from the received signals at the channel output. 

Attenuation – The loss of strength of a signal while it is propagated through a medium is known as attenuation. 

Amplification – the process through which the amplitude of a signal is increased is known as amplification. 

Along with these terms, you will also learn about range, bandwidth, modulation, demodulation, repeater etc. the chapter contains a detailed explanation of each of these terms and presents them in a very easy and simplified manner. 


In the course of modulation, it happens that the new frequencies termed as the sidebands are generated. These are generated on either side of the carrier by an amount that is equal to the highest modulating frequency. 

Amplitude Modulation 

The chapter deals with the amplitude modulation using a sinusoidal signal. There are formulas of the modulated signal and it has been properly explained with the help of diagrams, mathematical representations and examples. 

Exercise Discussion of NCERT Solutions for Class 12 Chapter 15 – Communication Systems

  • The exercise begins with an observation-based question where you are given where four different frequencies are given and you have to find out which of these would be suitable for a beyond – the – horizon communication by making use of sky waves. Here along with the observation, you need to justify your selection with a valid point. 
  • The next exercise 15.2 is also similar in terms of observation and then the justification. Here you are given different kinds of waves and you are supposed to find which of these would serve as the perfect means of propagation for the frequency of UHF range. 
  • Further, the chapter has very simple questions, like question 15.3 where you are given various statements with respect to the digital signals and you need to detect which statements from all the given options are true. 
  • Question 15.4 is a numerical based question where you are required to find the area of coverage for the service if the receiving antenna is placed at the ground level.  The height of the antenna is given in the question and you are required to find the solutions based on the concepts and formulas that you have learnt in the chapter. 
  • There are also diagram based questions in the chapter, like question 15.6 where a modulating signal square wave has been denoted in the figure and the value of the carrier wave and its voltage is given to you. In this question, you are asked to sketch the amplitude of the modulated waveform and derive its modulated index. 
  • Question 15.7 is also a numerical question where you have to use the direct formula, place the values and derive the answer to the question. Altogether these exercises are a very engaging way of revising and practising all the important portions of the chapter. 

Benefits of NCERT Solutions for Class 12 Physics Chapter 15 – Communication Systems

Instasolv’s team of expert and experienced professionals have left no stone unturned in covering each and every question from the chapter. All the solutions have been organized in a step by step and student-friendly manner, for your independent learning. The NCERT Solutions for chapter 15 have been formulated in accordance with the latest CBSE Syllabus.