*Question G6A11:
What happens when an inductor is operated above its self-resonant frequency?*  

*Correct Answer is  C: It becomes capacitive*  

### AI Response: (may contain errors)  

When an inductor is operated above its self-resonant frequency, it behaves differently than expected. Let's break down the correct answer and the reasoning behind it.

### Correct Answer: C - It becomes capacitive

- **Explanation**: 
  - An inductor has a self-resonant frequency where its inductive reactance ($X_L$) and the parasitic capacitance ($C_{p}$) are equal. Above this frequency, the capacitive effects dominate, and the inductor starts to behave like a capacitor. 
  - The self-resonant frequency ($f_{SR}$) can be calculated using the formula:
  
  $$
  f_{SR} = \frac{1}{2\pi\sqrt{L \cdot C_{p}}}
  $$

  where:
  - $L$ = inductance in henries
  - $C_{p}$ = parasitic capacitance in farads

### Why the Other Choices are Incorrect:

- **A: Its reactance increases**  
  - **Explanation**: Above the self-resonant frequency, the reactance does not increase; instead, the inductor's behavior shifts to being capacitive, which means the reactance decreases and becomes negative (indicative of capacitive behavior).

- **B: Harmonics are generated**  
  - **Explanation**: While operating an inductor at high frequencies can lead to non-linear effects and potential harmonics, this is not a direct consequence of operating above the self-resonant frequency. The primary effect is the shift to capacitive behavior.

- **D: Catastrophic failure is likely**  
  - **Explanation**: While excessive power or improper use can lead to failure, simply operating above the self-resonant frequency does not inherently cause catastrophic failure. The inductor may not perform as intended, but it does not guarantee failure.

### Summary

- Above the self-resonant frequency, an inductor behaves like a capacitor due to the dominance of its parasitic capacitance.
- Understanding the self-resonant frequency is crucial for predicting the behavior of inductors in high-frequency applications.