*Question E5D07:
What combines to create the self-resonance of a component?*  

*Correct Answer is  B: The component’s nominal and parasitic reactance*  

### AI Response: (may contain errors)  

To understand self-resonance in a component, we need to focus on how inductance and capacitance interact within that component.

### Correct Answer: B - The component’s nominal and parasitic reactance

- **Self-resonance** occurs when the inductive reactance ($X_L$) and capacitive reactance ($X_C$) of a component are equal, resulting in a net reactance of zero at a specific frequency. 
- **Nominal reactance** refers to the intended or designed reactance of the component, while **parasitic reactance** includes unintended effects due to the physical construction of the component (like stray capacitance or inductance).
- At the self-resonant frequency, the total reactance is zero, and the component behaves like a purely resistive element.

### Why the Other Choices are Incorrect:

- **A: The component’s resistance and reactance**
  - This choice is incorrect because self-resonance specifically involves the balance between inductive and capacitive reactance, not resistance. Resistance affects power loss but does not contribute to the resonance condition.

- **C: The component’s inductance and capacitance**
  - While inductance and capacitance are crucial for resonance, this choice does not account for the parasitic elements that can shift the self-resonant frequency. Self-resonance is more accurately described by the interaction of both nominal and parasitic reactances.

- **D: The component’s electrical length and impedance**
  - This choice is incorrect because electrical length and impedance relate to how a component interacts with a transmission line or circuit but do not directly define self-resonance. Self-resonance is specifically about the balance of reactances.

### Useful Concepts:

- The self-resonant frequency ($f_0$) can be calculated using the formula:

$$
f_0 = \frac{1}{2\pi\sqrt{LC}}
$$

where:
- $L$ = inductance in henries
- $C$ = capacitance in farads

- At self-resonance, the condition is:

$$
X_L = X_C
$$

This means that the inductive reactance ($X_L = 2\pi f L$) equals the capacitive reactance ($X_C = \frac{1}{2\pi f C}$) at the resonant frequency.

Understanding these concepts will help you grasp the nature of self-resonance and prepare effectively for the exam.