*Question T7C03:
What does a dummy load consist of?*  

*Correct Answer is  B: A non-inductive resistor mounted on a heat sink*  

### AI Response: (may contain errors)  

A dummy load is an essential component in amateur radio, used to safely dissipate RF power without radiating it. 

### Correct Answer: 
**B: A non-inductive resistor mounted on a heat sink**

- **Explanation**: 
  - A dummy load typically consists of a non-inductive resistor because it needs to convert RF energy into heat without introducing additional reactance that could affect the circuit. 
  - The heat sink is necessary to dissipate the heat generated by the resistor, preventing damage and ensuring reliable operation.

### Why the Other Choices are Incorrect:

- **A: A high-gain amplifier and a TR switch**  
  - This option describes components used for amplifying signals and switching between transmit and receive modes, not for dissipating RF power.

- **C: A low-voltage power supply and a DC relay**  
  - This choice refers to power supply components and switching mechanisms, which are unrelated to the function of a dummy load.

- **D: A 50-ohm reactance used to terminate a transmission line**  
  - While a dummy load does provide a termination for a transmission line, it must be resistive (not reactive) to effectively absorb power. A reactance would not dissipate power as heat.

### Summary:
A dummy load is crucial for testing and tuning transmitters without radiating signals. It must be a non-inductive resistor to ensure proper performance and avoid unwanted reactance.