Who among the following discovered change in the wavelength of light that occurs when a light beam is deflected by molecules?

C. V. Raman

The correct answer is Option (2) → C. V. Raman

The scientist who discovered the change in the wavelength of light when it is deflected by molecules is C. V. Raman.

This phenomenon is famously known as the Raman Effect (or Raman Scattering). He discovered it on February 28, 1928, a date now celebrated in India as National Science Day. For this groundbreaking work, Sir C. V. Raman became the first Indian and first Asian to receive the Nobel Prize in Physics in 1930.