What is the name of the phenomena in physics and astronomy which involves the splitting of a spectral line into two or more components of slightly different frequency when the light source is placed in a magnetic field?

Zeeman Effect

The correct answer is option 1. Zeeman Effect.

The phenomena in physics and astronomy which involves the splitting of a spectral line into two or more components of slightly different frequency when the light source is placed in a magnetic field is called the Zeeman Effect.

The Zeeman Effect was discovered by the Dutch physicist Pieter Zeeman in 1896 and is a fundamental phenomenon in atomic physics. It occurs due to the interaction between the magnetic field and the magnetic moment associated with the electrons in the atoms. The splitting of spectral lines in the presence of a magnetic field provides valuable information about the structure of atoms and the behavior of electrons within them.