Question

A 100 mH coil carries a current of 1 ampere. Energy stored in its magnetic field is

• A. 0.5 J
• B. 1 J
• C. 0.05 J
• D. 0.1 J

Answer 1

Answer: (C)

0.05 J

Answer 2

Energy $= \frac{1}{2}LI^{2} = \frac{1}{2} \times 100 \times 10^{- 3} \times 1^{2} = 0.05J$