EVALUATION

This end-of-unit EVALUATION block is the chapter's complete self-assessment, organised into four parts exactly as printed in the book. Part I, Multiple Choice Questions, has 15 objective questions (several drawn from NEET and KVPY past papers) covering photon-versus-electron wavelength relations, de Broglie wavelength calculations for electrons and other particles, stopping-potential and threshold-wavelength numericals built on Einstein's photoelectric equation, and simple recall of the different types of electron emission, with the book's own answer key provided alongside. Part II, Short Answer Questions, has 14 short, largely definitional questions -- covering free electrons in metals, the work function, the photoelectric effect, how photocurrent varies with intensity, the definition of light intensity, the threshold frequency, photocells and their types, the de Broglie wavelength expression for a charged particle, the de Broglie hypothesis itself, why macroscopic objects like a baseball show no observable wave behaviour, and simple comparisons of the de Broglie wavelengths of different particle pairs. Part III, Long Answer Questions, has 13 questions demanding fuller explanation or derivation -- the various methods of electron emission, the Hertz-Hallwachs-Lenard observations, the effects of potential difference and frequency on photoelectric current, the laws of the photoelectric effect, why wave theory fails to explain the effect, the quantum concept of light, the derivation of Einstein's photoelectric equation and how it explains the observed facts, the construction and working of the photo emissive cell, the derivation of the electron's de Broglie wavelength, the principle of the electron microscope, and a description of the Davisson-Germer experiment. Part IV, Numerical Problems, has 15 fully worked-numerical-style questions spanning photon counting from lamps and laser …