Question
What is the relationship between the AC current through a capacitor and the voltage across a capacitor?
Answer Options
- A) Voltage and current are in phase
- B) Voltage and current are 180 degrees out of phase
- C) Voltage leads current by 90 degrees
- D) Current leads voltage by 90 degrees
Correct Answer: D
Explanation
The relationship between AC voltage and current in a reactive component defines the phase angle of the component. A capacitor stores energy in an electric field, and the voltage across it is determined by the rate of change of the current. This process always results in a phase shift between the two quantities.
For a purely capacitive circuit, the current leads the voltage by 90 degrees. This relationship is often remembered by the mnemonic ‘ICE man,’ where ‘I’ (current) leads ‘E’ (voltage) in a ‘C’ (capacitive) circuit. The current must rush in to change the charge, and thus the voltage, of the capacitor.
This topic was automatically created to facilitate community discussion about this exam question. Feel free to share study tips, memory tricks, or additional explanations!