Frequencies of various radiations are given as
`f_(v) to` Visible light
`f_(r ) to` Radio waves
`f_(uv) to` Ultra Violet waves
The which of the following is true?

Options

A. `f_(uv) = f_(v) lt f_(r )`
B. `f_(r) lt f_(v) lt f_(uv)`
C. `f_(v) , f_(r) lt f_(uv)`
D. `f_(uv) , f_(r ) lt f_(v )`

Answer

To solve the problem, we need to compare the frequencies of various types of electromagnetic radiation: visible light (f_v), radio waves (f_r), and ultraviolet waves (f_uv).

### Step-by-Step Solution:

1. **Understanding the Electromagnetic Spectrum**:
- The electromagnetic spectrum is divided into different regions based on wavelength and frequency. The regions include gamma rays, X-rays, ultraviolet (UV) light, visible light, infrared, microwaves, and radio waves.

2. **Identifying Wavelength Ranges**:
- **Ultraviolet (UV)**: Wavelengths shorter than visible light, typically from about 10 nm to 400 nm.
- **Visible Light**: Wavelengths range from approximately 400 nm (violet) to 700 nm (red).
- **Radio Waves**: Wavelengths are much longer, starting from about 1 mm to several kilometers.

3. **Frequency and Wavelength Relationship**:
- The frequency (f) of electromagnetic radiation is inversely proportional to its wavelength (λ) as described by the equation:
\[ c = f \cdot \lambda \]
where \(c\) is the speed of light (approximately \(3 \times 10^8\) m/s).
- This means that as the wavelength increases, the frequency decreases.

4. **Comparing Frequencies**:
- Since UV light has the shortest wavelength, it has the highest frequency.
- Visible light has a longer wavelength than UV, so its frequency is lower than that of UV light.
- Radio waves have the longest wavelengths and therefore the lowest frequencies.

5. **Conclusion**:
- Based on the above analysis, we can establish the order of frequencies:
\[ f_{uv} > f_{v} > f_{r} \]
- Therefore, the correct statement is that the frequency of ultraviolet waves (f_uv) is greater than that of visible light (f_v), which in turn is greater than that of radio waves (f_r).

### Final Answer:
The correct order of frequencies is:
\[ f_{uv} > f_{v} > f_{r} \]