WAEC Physics 2024 Objective — Question 38
Question 38 of 50 from the West African Examinations Council (WAEC) Physics 2024 Objective paper, with the correct answer and a full explanation.
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38. Which of the following modes is the most economical method of transmitting electrical power over a long distance? A.
- A. Alternating current at high voltage and low current.Correct
- B. Alternating current at low voltage and high current.
- C. Direct current at high voltage and high current.
- D. Direct current at low voltage and low current.
Explanation
Recall that power loss due to resistance in the transmission lines is given by P=I^2R. Thus, by transmitting at high voltage and low current, I is minimized, significantly reducing power loss.
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