splitting of spectral lines under the influences of magnetic field is called

Options

A. photo electric effect
B. stark effect
C. Crompton effect
D. Zeeman effect

Answer

To answer the question regarding the splitting of spectral lines under the influence of a magnetic field, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Spectral Lines**: Spectral lines are the distinct lines of color produced when light is emitted or absorbed by atoms. Each element has a unique spectral line pattern.

2. **Influence of Magnetic Field**: When a magnetic field is applied to a sample of atoms, the energy levels of the electrons in those atoms can be altered. This phenomenon is due to the interaction between the magnetic field and the magnetic moments associated with the electrons.

3. **Definition of the Effect**: The splitting of these spectral lines due to the presence of a magnetic field is a specific phenomenon.

4. **Terminology**: The term used to describe this splitting is known as the **Zeeman Effect**.

5. **Conclusion**: Therefore, the splitting of spectral lines under the influence of a magnetic field is called the Zeeman Effect.

### Final Answer:
The splitting of spectral lines under the influence of a magnetic field is called the **Zeeman Effect**.