A carbon microphone is best used in a

Options

A. dynamo
B. telephone
C. transformer
D. none of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Function of a Microphone:**
- A microphone is a device that converts sound waves into electrical signals. When sound waves hit the microphone, they cause a diaphragm to vibrate.

2. **Identifying the Type of Microphone:**
- In this case, we are specifically looking at a carbon microphone. It consists of two main components: a flexible diaphragm and a fixed electrode.

3. **How a Carbon Microphone Works:**
- When sound waves are produced (for example, when someone speaks into the microphone), the diaphragm vibrates.
- These vibrations compress and decompress carbon granules located between the diaphragm and the fixed electrode.

4. **Change in Resistance:**
- As the diaphragm vibrates, the pressure on the carbon granules changes, which in turn alters the resistance of the carbon granules.
- This change in resistance is converted into an electrical signal.

5. **Application of Carbon Microphone:**
- The carbon microphone is primarily used in telephones. It is essential for converting the sound of a person's voice into an electrical signal that can be transmitted over distances.

6. **Conclusion:**
- Therefore, the correct answer to the question is that a carbon microphone is best used in a **telephone**.

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