Answer: Power loss P = I²R decreases when voltage is stepped up and current is stepped down.
- A Power loss P = I²R decreases when voltage is stepped up and current is stepped down
- B Higher voltage transmission is inherently safer for line workers according to conventional understanding
- C Higher voltage transmission requires fewer step-up transformers overall in routine practice
- D Transmission cables can be made thinner generally by raising the voltage overall
Correct answer: A. Power loss P = I²R decreases when voltage is stepped up and current is stepped down
Explanation: For a given power P = VI, increasing V reduces I. Power loss in wires = I²R, so reducing I dramatically reduces transmission losses.
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.