CBSE Class 12 Physics Notes Chapter 15 Communication Systems

According to the CBSE Syllabus 2023-24, this chapter has been removed from NCERT Class 12 Physics textbook.

What Is Electronic Communication?

The faithful transformation of a message or information is known as electronic communication, which can be available in the form of electrical current or voltage travelling from one point to another.

Basic Units of a Communication System

The basic units of a communication system are:

  • Transmitter
  • Transmission Channel
  • Receiver

Forms of the Communication System

The information usually is in the form of a continuous waveform. There are two forms of a communication system;

  • Analog
  • Digital

The Bandwidth of a System

Every message signals constitute various ranges of frequencies, which are very vital for the necessary and optimal transmission of information in the signal. Any practical communication supports a few ranges of frequencies.

What Is Modulation?

Frequencies which are low cannot travel long distances, and for that, they are being superimposed with a high-frequency carrier signal in order to flow smoothly. They are various types of modulation:

  • Pulse Position Modulation (PPM)
  • Pulse Width Modulation (PWM)
  • Pulse Duration Modulation (PDM)
  • Pulse Amplitude Modulation (PAM)

Important Questions

  1. The maximum amplitude and minimum amplitude for an amplitude-modulated wave are found to be 20V and 2V, respectively. Determine the modulation index, µ and find out the value of µ if the minimum amplitude is zero volts.
  2. In order to have a modulation index of 85%, what should be the peak voltage of the modulating signal if the carrier wave has a peak voltage of 15V and is used to transmit a message signal?

Related Topics:

CBSE Notes for Physics Class 12

NCERT Solutions for Class 12 Physics Chapter 15

NCERT Exemplar for Class 12 Physics Chapter 15

Electronic Communication Systems

Frequently Asked Questions on CBSE Class 12 Physics Notes Chapter 15 Communication Systems


What is electronic communication?

Electronic communication is any form of communication that’s broadcast, transmitted, stored or viewed using electronic media, such as computers, phones, email and video.


What is a transmission channel?

A path between two nodes in a network. It may refer to the physical cable, the signal transmitted within the cable or a subchannel within a carrier frequency.


What is an analog signal?

An analog signal is a continuous signal in which one time-varying quantity represents another time-based variable.


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