Match List-I with List-II.
| List-I | List-II |
| (A) Photoelectric effect | (I) de Broglie |
| (B) Wave-particle duality | (II) Roentgen |
| (C) X-rays | (III) R. A. Millikan |
| (D) Quantised electric charge | (IV) Heinrich Hertz |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
(A) Photoelectric effect — This matches (IV) Heinrich Hertz. He discovered photoelectric emission in 1887 during his experiments on electromagnetic waves. He saw that the sparks across his detector grew stronger when the emitter plate was lit by ultraviolet light.
(B) Wave-particle duality — This matches (I) de Broglie. He proposed that matter, like radiation, has a dual nature. His relation \( \lambda=h/p \) links a wave attribute, the wavelength, to a particle attribute, the momentum.
(C) X-rays — This matches (II) Roentgen, who discovered X-rays in 1895 in experiments on electric discharge through gases.
(D) Quantised electric charge — This matches (III) R. A. Millikan, who showed by experiment that every charge is an integral multiple of the electronic charge \( e \).
NCERT (2026-27):
Hertz’s Observations – “The phenomenon of photoelectric emission was discovered in 1887 by Heinrich Hertz (1857-1894), during his electromagnetic wave experiments.”
Wave Nature of Matter – “… The dual aspect of matter is evident in the de Broglie relation.”
Introduction – “… The discovery of X-rays by Roentgen in 1895, and of electron by J. J. Thomson in 1897, were important milestones in the understanding of atomic structure.”
Quantisation of Charge – “The fact that electric charge is always an integral multiple of e is termed as quantisation of charge. … It was experimentally demonstrated by Millikan in 1912.”