Homi Jahangir Bhabha played an important role in the discovery of ____.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Quantum theory
Homi Jehangir Bhabha, the father of India’s nuclear programme, made his name in quantum theory, in the part of it that deals with electrons, positrons and cosmic rays. In 1935 he worked out how an electron and a positron scatter off each other, now called Bhabha scattering, and in 1937, with Walter Heitler, he explained the showers of particles that cosmic rays produce in the atmosphere (the cascade theory).
Why the other options are incorrect
Option (1) Photoelectric effect — Incorrect. The emission of electrons by light falling on a metal was explained by Albert Einstein in 1905.
Option (3) Photosynthesis — Incorrect. It is the process by which green plants make food from carbon dioxide and water using sunlight, a part of biology.
Option (4) Nucleus Discovery — Incorrect. The atomic nucleus was discovered by Ernest Rutherford in 1911, from his gold foil experiment.