25 percent
50 percent
2-wire feeder is increased 100 percent, saving in copper is A. 25 percent B. 50 percent C. 75 percent
100 percent
Answer is Wrong!
Answer is Right!
The correct answer is $\boxed{\text{B. 50 percent}}$.
The current in a DC circuit is inversely proportional to the voltage. If the supply voltage is increased by 100%, the current will decrease by 50%. The power loss in a conductor is proportional to the square of the current. Therefore, if the current is decreased by 50%, the power loss will be decreased by 75%.
The copper used in a DC 2-wire feeder is used to carry the current. If the power loss is decreased by 75%, then the amount of copper required to carry the same amount of power can be decreased by 50%.
Here is a more detailed explanation of each option:
- Option A: 25 percent. This is incorrect because the power loss is decreased by 75%, not 25%.
- Option B: 50 percent. This is the correct answer because the power loss is decreased by 75%, and the amount of copper required to carry the same amount of power is decreased by 50%.
- Option C: 75 percent. This is incorrect because the power loss is decreased by 75%, not 75%.
- Option D: 100 percent. This is incorrect because the power loss is decreased by 75%, not 100%.