Monochromatic light passes through prism. Compared to that in air. Inside the prism the light's

Options

A. speed and wavelength are different but frequency remains same
B. speed and frequency are different but wavelength remains same
C. wavelength and frequency are different, but speed remains same
D. speed, wavelength and frequency are all different

Answer

To solve the question about the behavior of monochromatic light as it passes through a prism, we can break down the steps as follows:

### Step-by-Step Solution:

1. **Understanding Monochromatic Light**:
- Monochromatic light refers to light that has a single wavelength and frequency. This means that while the light is passing through different mediums, its frequency remains constant.

2. **Frequency in Different Mediums**:
- The frequency of light does not change when it moves from one medium to another. Therefore, when monochromatic light enters the prism, its frequency remains the same as it was in air.

3. **Wavelength Change**:
- The speed of light in different mediums varies. In air, the speed of light is approximately \( c \) (the speed of light in vacuum), while in a prism (usually made of glass), the speed of light is less than \( c \).
- The relationship between speed (v), frequency (f), and wavelength (λ) is given by the equation:
\[ v = f \cdot \lambda \]
- Since the frequency (f) remains constant and the speed (v) decreases in the prism, the wavelength (λ) must also decrease.

4. **Conclusion**:
- Therefore, when monochromatic light passes through a prism, the frequency remains the same, but the speed and wavelength of the light change.

5. **Identifying the Correct Option**:
- Based on the analysis, we conclude that the correct option is that the frequency remains the same, while the speed and wavelength change.

### Final Answer:
- The correct option is **A**: The frequency remains the same, but the wavelength and speed change.