Question
What is the primary cause of loss in film capacitors at RF?
Answer Options
- A) Inductance
- B) Dielectric loss
- C) Self-discharge
- D) Skin effect
Correct Answer: D
Explanation
All capacitors exhibit some level of internal energy dissipation (loss), which is usually modeled as an Equivalent Series Resistance (ESR). This loss prevents the capacitor from being a perfect energy storage device. In high-quality film capacitors used at RF, two main causes of loss are parasitic resistance in the leads/foils and losses within the insulating material itself.
The primary cause of loss in film capacitors at RF is Skin effect. This is because alternating current is forced to flow only along the thin outer surface of the metal electrode film. This reduction in the usable cross-sectional area causes higher Equivalent Series Resistance (ESR) at RF frequencies, which is dissipated as heat.
This topic was automatically created to facilitate community discussion about this exam question. Feel free to share study tips, memory tricks, or additional explanations!