*Question G0B12:
What is the purpose of a power supply interlock?*  

*Correct Answer is  C: To ensure that dangerous voltages are removed if the cabinet is opened*  

### AI Response: (may contain errors)  

The correct answer to the question about the purpose of a power supply interlock is:

**C: To ensure that dangerous voltages are removed if the cabinet is opened.**

### Explanation of the Correct Answer:
- **Purpose of Power Supply Interlock**: The primary function of a power supply interlock is to enhance safety. When the cabinet of a device is opened, the interlock mechanism ensures that the power supply is disconnected, thereby removing dangerous voltages that could pose a risk of electric shock to the user. This is crucial in preventing accidents during maintenance or inspection.

### Why the Other Choices are Incorrect:
- **A: To prevent unauthorized changes to the circuit that would void the manufacturer’s warranty**  
  - This is incorrect because the interlock is not designed to monitor warranty conditions or prevent unauthorized modifications. Its main focus is on safety rather than warranty enforcement.

- **B: To shut down the unit if it becomes too hot**  
  - While overheating protection is important, it is typically managed by thermal sensors or fuses, not by an interlock. The interlock specifically addresses safety when accessing the internal components.

- **D: To shut off the power supply if too much voltage is produced**  
  - This is also incorrect. Voltage regulation and over-voltage protection are handled by different circuits and components, such as voltage regulators or protective relays, rather than by an interlock mechanism.

### Summary:
- The interlock is a safety feature that disconnects power when the cabinet is opened, preventing exposure to high voltages.
- Other options relate to different safety or operational functions that are not the primary role of a power supply interlock.

This understanding is essential for ensuring safe operation and maintenance of radio equipment and other electronic devices.