Question

What is the term used for explaining the process of splitting spectral lines in presence of an electric field?

Answer 1

1. Stark effect: The Stark effect refers to the splitting of a spectral line in the presence of an electric field. Johannes Stark, a German scientist, developed this phenomenon.
2. Stark observed the hydrogen spectrum generated by a positive-ray tube's punctured cathode. He was successful in building an electric field within a few $\mathrm{centimeters}$ with a second energized electrode parallel as well as near to this cathode.

Therefore, the term which is used for explaining the process of splitting spectral lines in presence of an electric field is called the stark effect.