If the wavelength of light in vacuum be `lambda`, the wavelength in a medium of refractive index n will be

Options

A. `nlambda`
B. `lambda/n`
C. `lambda/n^(2)`
D. `n^(2)lambda`

Answer

To find the wavelength of light in a medium with a refractive index \( n \), given that the wavelength in vacuum is \( \lambda \), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Relationship**: The wavelength of light changes when it passes from one medium to another due to the change in speed of light in that medium. The relationship between the wavelength in vacuum and the wavelength in a medium is given by the formula:
\[ \lambda' = \frac{\lambda}{n} \]
where:
- \( \lambda' \) is the wavelength in the medium,
- \( \lambda \) is the wavelength in vacuum,
- \( n \) is the refractive index of the medium.

2. **Identify Given Values**: From the question, we know:
- Wavelength in vacuum \( \lambda \),
- Refractive index of the medium \( n \).

3. **Apply the Formula**: Substitute the known values into the formula:
\[ \lambda' = \frac{\lambda}{n} \]

4. **Conclusion**: The wavelength of light in the medium with refractive index \( n \) is:
\[ \lambda' = \frac{\lambda}{n} \]

### Final Answer:
The wavelength in the medium is \( \frac{\lambda}{n} \).

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