NCERT Exemplar Solutions for Class 12 Physics Chapter 11 – Dual Nature of Radiation and Matter

About NCERT Exemplar Solutions for Class 12 Physics Chapter 11 – Dual Nature of Radiation and Matter

The eleventh chapter of Class 12 Physics, Dual Nature of Radiation and Matter, introduces students to one of the most groundbreaking discoveries in modern physics—the dual character of both light and matter. This chapter explains how light, which was once thought to behave only as a wave, also exhibits particle-like behavior, and how matter, generally treated as particulate, shows wave-like properties at microscopic scales. The NCERT Exemplar Solutions for this chapter provide carefully structured problems that help learners strengthen their understanding of this fascinating subject and prepare for both board and competitive examinations. The chapter begins with a discussion of the photoelectric effect, which revealed the particle nature of light. The Exemplar Solutions present problems based on Einstein’s photoelectric equation, work function, threshold frequency, and stopping potential. By solving these problems, students understand the relationship between the energy of incident photons and the emission of electrons from a metal surface. These problems also emphasize why classical wave theory failed to explain the photoelectric effect, thereby highlighting the significance of quantum theory. The Exemplar Solutions also focus on experimental verification of the photoelectric effect and its implications. Questions test conceptual clarity on factors affecting photoelectric current, such as intensity, frequency of incident light, and the nature of the metal surface. This helps learners connect theoretical knowledge with practical laboratory observations. Another important concept covered in this chapter is the wave nature of matter. The NCERT Exemplar Solutions provide practice problems based on de Broglie’s hypothesis, which associates a wavelength with moving particles. By solving numerical questions on de Broglie wavelength for electrons, protons, and other particles, students appreciate the universality of this principle.

The Exemplar also includes problems on Davisson and Germer’s experiment, which provided direct evidence of electron diffraction. Through these solutions, learners understand how the wave-like behavior of matter was experimentally confirmed, marking a milestone in quantum mechanics. Towards the end, the chapter highlights applications of dual nature, such as electron microscopes and the significance of wave-particle duality in modern science. The Exemplar questions push students to think critically about how the same entity can exhibit two different behaviors depending on the context, reinforcing higher-order thinking. In conclusion, the NCERT Exemplar Solutions for Dual Nature of Radiation and Matter are an invaluable resource for mastering this pivotal chapter. The well-explained problems help students build confidence in handling conceptual questions and numerical applications alike. By practicing these solutions, learners not only prepare thoroughly for board exams but also gain a strong foundation in quantum physics necessary for competitive exams like JEE and NEET.