About NCERT Exemplar Solutions for Class 12 Physics Chapter 15 – Communication Systems
The fifteenth and final chapter of Class 12 Physics, Communication Systems, introduces students to the fascinating world of information transfer and the science behind modern communication technologies. From radio and television to mobile phones and satellites, communication has become an inseparable part of human life, and this chapter helps students understand the fundamental principles behind it. The NCERT Exemplar Solutions for this chapter serve as a comprehensive practice guide, offering conceptual and numerical problems that strengthen understanding and application of the topic. The chapter begins with a historical overview of communication, tracing the journey from simple signaling methods to advanced digital systems. The Exemplar Solutions include questions that help students recognize the basic elements of a communication system – the transmitter, the communication channel, and the receiver. By practicing these, learners develop clarity about how information is generated, transmitted, and received across various mediums. A significant part of the chapter is dedicated to the concept of the electromagnetic spectrum. The Exemplar Solutions provide problems that test knowledge of different frequency ranges and their applications in communication technologies. This helps students connect theory with real-life applications such as AM radio, FM radio, and television broadcasting.
Another major topic is modulation, which is essential for efficient communication. The Exemplar Solutions present problems on amplitude modulation, frequency modulation, and phase modulation. Students learn why modulation is required, how bandwidth is related to transmitted signals, and how carrier waves play a role in transmitting information over long distances. Numerical problems further reinforce the understanding of modulation index, sidebands, and power distribution in modulated waves. The chapter also explains the process of demodulation and detection of signals at the receiver’s end. Exemplar questions guide students through practical problem-solving, ensuring they understand how the original message is retrieved from a modulated signal. Propagation of waves through the atmosphere is another area emphasized in the Exemplar Solutions. Problems cover ground wave, sky wave, and space wave propagation, along with their respective uses and limitations. These exercises prepare students to analyze which mode of propagation is suitable for different frequency ranges and applications. The chapter concludes with modern communication technologies such as satellite communication and optical fiber communication. The Exemplar Solutions provide questions that highlight advantages like high bandwidth, low signal loss, and wide coverage, enabling students to appreciate the efficiency of current systems. In conclusion, the NCERT Exemplar Solutions for Communication Systems provide a balanced combination of theory-based and numerical problems. By practicing them, students not only gain confidence for board exams but also build a strong conceptual base that links physics with real-world applications. This chapter helps learners understand how scientific principles drive the communication revolution that connects people across the globe.