*Question T6A02:
What type of component is often used as an adjustable volume control?*  

*Correct Answer is  C: Potentiometer*  

### AI Response: (may contain errors)  

The correct answer to the question about adjustable volume control is **C: Potentiometer**. Here's why:

### Why the Correct Answer is Correct:
- A **potentiometer** is a three-terminal resistor that can be adjusted to provide variable resistance. It is commonly used in audio equipment as a volume control because it allows the user to change the resistance in the circuit, thereby adjusting the audio signal level.

### Why the Other Choices are Incorrect:
- **A: Fixed resistor**  
  - A fixed resistor has a constant resistance value and cannot be adjusted. It is not suitable for applications requiring variable control, such as volume adjustment.

- **B: Power resistor**  
  - A power resistor is designed to handle high power levels and has a fixed resistance. Like fixed resistors, they do not allow for adjustment and are not used for volume control.

- **D: Transformer**  
  - A transformer is used to change the voltage level in AC circuits and does not provide variable resistance. It is not applicable for controlling volume in audio systems.

### Useful Information:
- Potentiometers are often used in audio applications, and their resistance value is typically measured in ohms (Ω). The adjustment mechanism can be linear or logarithmic, with logarithmic being more common for audio applications to match human hearing sensitivity.

In summary, a potentiometer is the ideal component for adjustable volume control due to its ability to vary resistance, while the other options do not provide this functionality.