Question

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

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

Answer 1

Answer: (C)

0.05 J

Answer 2

Energy stored $E=\frac{1}{2}L{{I}^{2}}$ $=\frac{1}{2}\times 100\times {{10}^{-3}}\times {{(1)}^{2}}=0.05J$