Given below is a list of electromagnetic spectrum and its mode of production. Which one does not match?  

Options

A. Gamma rays - Radioactive decay of the nucleus
B. Ultraviolet - Magnetron valve
C. Infra-red - Vibration of atoms and molecules
D. X-rays - Coolidge tube

Explanation

To solve the problem of identifying which mode of production does not match with the electromagnetic spectrum, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Electromagnetic Spectrum**: The electromagnetic spectrum consists of various types of waves, including gamma rays, x-rays, ultraviolet (UV) rays, microwaves, and infrared waves. Each type of wave is produced through different mechanisms.

2. **Identify the Modes of Production**:
- **Gamma rays**: Produced by radioactive decay of atomic nuclei.
- **X-rays**: Generated using a Coolidge tube, which involves high-energy electrons colliding with a target material.
- **Ultraviolet (UV) rays**: Produced by high-temperature bodies (like the sun) or through gaseous electric discharge.
- **Microwaves**: Generated using a magnetron, which is a type of vacuum tube.
- **Infrared waves**: Produced by the vibrations of atoms and molecules.

3. **Match Each Type of Wave with Its Production Method**:
- Gamma rays → Radioactive decay (Correct)
- X-rays → Coolidge tube (Correct)
- UV rays → High-temperature body or gaseous electric discharge (Correct)
- Microwaves → Magnetron (Correct)
- Infrared → Vibrations of atoms and molecules (Correct)

4. **Identify the Mismatch**: Upon reviewing the relationships, we find that the statement regarding UV rays being produced by a magnetron is incorrect. UV rays are not produced by a magnetron; they are produced by high-temperature bodies or gaseous electric discharge.

5. **Conclusion**: The incorrect match is the one that states UV rays are produced by a magnetron. Therefore, the answer to the question is that the option related to UV rays and magnetron does not match.

### Final Answer:
The mismatch is: **Ultraviolet rays produced by a magnetron**.

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