Chapter 11: Dual Nature of Radiation and Matter
NCERT Class 12 Physics, Part II, Chapter 11. 6 lessons, 14 narrated 3D videos, 6 simulations and 12 quiz questions, following the textbook section by section.
- Electron emissionLate in the nineteenth century, scientists passed electricity through gases at very low pressure, in discharge tubes. At a pressure of about 0.001 millimetre of mercury,…
- The photoelectric effectIn 1887, Heinrich Hertz was making electromagnetic waves with sparks jumping across a gap between two metal knobs. He noticed something strange: the sparks jumped more…
- Photoelectric effect and the wave theoryBy the end of the nineteenth century, everyone agreed that light is a wave. Interference, diffraction and polarisation were all explained by waves, and Maxwell showed…
- Einstein’s equation and the photonIn 1905, Albert Einstein made a bold proposal. Light energy is not spread out continuously. It comes in discrete packets, called quanta, each of energy h ν, where ν is…
- Wave nature of matterLight has a dual nature. In interference and diffraction it behaves as a wave. In the photoelectric effect it behaves as a stream of particles, photons.
- The Davisson–Germer experimentThis experiment is no longer in the current NCERT syllabus, but it is a classic, and it is useful for competitive exams. It is the experiment that showed de Broglie was…