In real-world components, which characteristics does a practical inductor exhibit in addition to ideal inductance?

Introduction / Context:
No manufactured inductor behaves as an ideal element. Practical coils exhibit parasitic resistance and capacitance that shape frequency response, losses, and self-resonance. Recognizing these non-idealities is essential for RF design, switching power supplies, and precision filtering.

Given Data / Assumptions:

• Wound inductor with finite wire resistivity and inter-turn spacing.
• Operation over a range of frequencies where parasitics become significant.
• Linear operation (no core saturation) for the conceptual discussion.

Concept / Approach:
A practical inductor can be modeled as an ideal inductance L in series with a winding resistance R_w (copper loss), and in parallel (or distributed) with a capacitance C_p due to inter-turn and layer-to-layer capacitances. At low frequency, R_w causes I^2*R loss; at high frequency, C_p can resonate with L, creating a self-resonant frequency beyond which the device behaves capacitively.

Step-by-Step Solution:
Identify ideal property: inductance L stores energy in a magnetic field.Add series resistance: R_w represents copper loss and skin/proximity effects at higher frequencies.Add parasitic capacitance: C_p arises from the proximity of turns and insulation.Conclude: a practical inductor exhibits all of these characteristics simultaneously.

Verification / Alternative check:
Impedance analyzer sweeps show rising inductive reactance up to a peak at self-resonance, after which the inductor appears capacitive—evidence of C_p. DC resistance measurements reveal R_w.

Why Other Options Are Wrong:
Choosing only one property ignores well-documented parasitics present in every coil.

Claiming “only inductance with zero loss” contradicts reality; wire has resistance and dielectrics form capacitance.

Common Pitfalls:
Using an inductor near or above its self-resonant frequency without accounting for the capacitive behavior. Always check datasheet curves.

Final Answer:
all of the above