*Question T9B10:
What is the electrical difference between RG-58 and RG-213 coaxial cable?*  

*Correct Answer is  C: RG-213 cable has less loss at a given frequency*  

### AI Response: (may contain errors)  

The correct answer to the question about the electrical difference between RG-58 and RG-213 coaxial cable is:

**C: RG-213 cable has less loss at a given frequency.**

### Explanation of the Correct Answer:
- **Loss Characteristics**: RG-213 is a thicker coaxial cable compared to RG-58, which results in lower attenuation (signal loss) over distance. The attenuation of coaxial cables is typically measured in decibels per 100 feet (dB/100 ft) at a specific frequency. RG-213 has a lower dB/100 ft rating than RG-58, making it more efficient for longer runs or higher frequency applications.

### Why the Other Choices are Incorrect:
- **A: There is no significant difference between the two types**  
  This is incorrect because there are notable differences in construction, size, and electrical performance, particularly in terms of loss and power handling.

- **B: RG-58 cable has two shields**  
  This is incorrect. RG-58 typically has a single shield (usually a braid), while RG-213 can have a more robust shielding configuration, but it is not defined by having two shields.

- **D: RG-58 cable can handle higher power levels**  
  This is incorrect. RG-213 is designed to handle higher power levels due to its larger diameter and better insulation, making it suitable for high-power applications.

### Useful Formulas and Rules of Thumb:
- **Attenuation Formula**: The attenuation (loss) in coaxial cables can be approximated by the formula:
  
  $$ 
  A = \frac{P_{in} - P_{out}}{L} 
  $$

  where:
  - $A$ = attenuation in dB/100 ft
  - $P_{in}$ = input power in watts
  - $P_{out}$ = output power in watts
  - $L$ = length of the cable in feet

- **General Rule of Thumb**: For most applications, RG-213 is preferred over RG-58 for longer runs or higher frequencies due to its lower loss characteristics. 

This understanding will help you choose the appropriate coaxial cable for your amateur radio setups and ensure efficient signal transmission.