Answer: It dissipates very little power while limiting current.
- A It dissipates very little power while limiting current
- B A choke coil is generally cheaper to manufacture than a resistor
- C It has a much higher ohmic resistance than an equivalent resistor
- D It amplifies the AC current instead of limiting it
Correct answer: A. It dissipates very little power while limiting current
Explanation: A choke has low resistance but high reactance (X<sub>L</sub> = ωL). It limits AC current without significant power dissipation (P = I²R ≈ 0 since R is small).
In a pure inductor the current lags the voltage by 90° (energy is briefly stored in the magnetic field before current responds); in a pure capacitor the current leads the voltage by 90° (current must flow to build up charge before voltage rises) - the mnemonic "ELI the ICE man" keeps these straight.
Concept context
AC circuits, impedance, LCR series circuit, resonance, transformers, and power factor.