Energy stored by a coil is doubled when its current is increased by percent___________?
Correct answer: C. 41.4
- A. 25
- B. 50
- C. 41.4
- D. 100
Explanation
The energy stored in a coil is W = ½LI², so doubling the energy requires the current to become √2 times its original value. The percentage increase is (√2 − 1) × 100 ≈ 41.4%.
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