Question

The energy stored in a 50 mH inductor carrying a current of 4 A will be

• A. 0.4 J
• B. 4.0 J
• C. 0.8 J
• D. 0.04 J

Answer 1

Answer: (A)

0.4 J

Answer 2

$U = \frac{1}{2}Li^{2} = \frac{1}{2} \times (50 \times 10^{- 3}) \times (4)^{2} = 400 \times 10^{- 3} = 0.4J$