Answer: 20 A.
- A 0.2 A
- B 2 A
- C 20 A
- D 200 A
Correct answer: C. 20 A
Explanation: Turns ratio = 10, so voltage ratio = 10: Vs = 2200 V. Power: Vp x Ip = Vs x Is = 2200 x 2 = 4400. Ip = 4400/220 = 20 A.
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.