Physics · Class 12 · Chapter 11
Dual Nature of Radiation and Matter
11 lessons99 min5 simulations10 practice questions
Light that behaves as a wave in interference and diffraction behaves as a stream of particles when it knocks electrons out of a metal. This chapter follows the photoelectric experiments, shows why the wave picture cannot explain them, and builds Einstein's equation Kmax = hν − φ₀ on the idea of the photon. It then turns the argument round: de Broglie gave every moving particle a wavelength λ = h/p.
Also called: photoelectric effect · de Broglie wavelength · modern physics
Lessons
11 lessons · 99 min
01Electron emissionNCERT §11.1, §11.28 min02Discovery of the photoelectric effectNCERT §11.36 min03The photoelectric experimentNCERT §11.4, §11.4.16 min04Saturation current and stopping potentialNCERT §11.4.210 min1 sim05Threshold frequency and no time lagNCERT §11.4.37 min06Where the wave picture failsNCERT §11.59 min1 sim07Einstein's photoelectric equationNCERT §11.611 min1 sim08The photonNCERT §11.710 min1 sim09Matter waves and de BroglieNCERT §11.87 min10How long is a matter wave?NCERT §11.810 min1 sim11Chapter reviewMust-know facts, traps and formulas15 min
Simulations
5 in this chapter