Assuming transmitted power remains constant, raising the supply voltage of a 2-wire D.C. feeder by 100 percent results in a copper saving of____________________?
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Answer: C. 75 percent
Explanation
For a fixed transmitted power, doubling the voltage halves the current. Conductor cross-section is set by the current it must carry, so the copper needed falls to a quarter of what it was, a saving of 75 per cent. This is why long transmission lines run at the highest voltage the insulation will bear.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
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