The contrast in the fringes in any interference pattern depends on:

Options

A. Fringe width
B. wavelength
C. Intensity ratio of the sources
D. Distance between the sources

Answer

To solve the question regarding the contrast in the fringes of an interference pattern, we will analyze the factors that influence the visibility and contrast of the fringes.

### Step-by-Step Solution:

1. **Understanding Interference**:
- Interference occurs when two coherent light sources emit waves that overlap. The resulting pattern consists of bright and dark fringes due to constructive and destructive interference.

2. **Identifying Key Factors**:
- The contrast in the interference pattern is influenced by several factors, including the wavelength of the light, the fringe width, the intensity of the sources, and the distance between the sources.

3. **Focusing on Intensity**:
- The contrast of the fringes is primarily determined by the intensity of the light waves from the two sources. If the intensities of the two sources are significantly different, the contrast will be higher. Conversely, if the intensities are similar, the contrast will be lower.

4. **Mathematical Representation**:
- The intensity of the light waves can be represented as \( I_1 \) and \( I_2 \) for the two sources. The contrast (visibility) of the fringes can be expressed as a function of the ratio of these intensities:
\[ \text{Contrast} \propto \frac{I_1 - I_2}{I_1 + I_2} \]
- This shows that the difference in intensities directly affects the visibility of the fringes.

5. **Conclusion**:
- Based on the analysis, we conclude that the contrast in the fringes of an interference pattern depends on the intensity ratio of the two sources. Therefore, the correct answer is option C: intensity ratio of the sources.

### Final Answer:
The contrast in the fringes in any interference pattern depends on the intensity ratio of the sources.

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