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The energy stored in an inductor of inductance $L$ carrying a steady current $I$ is:
A$L I^2$
B$\dfrac{1}{2} L I^2$
C$\dfrac{1}{2} L^2 I$
D$LI$
Answer & Solution
Correct answer: B. $\dfrac{1}{2} L I^2$
Work done by the source against the back-EMF while the current grows from $0$ to $I$ is $W = \int_0^I L i\,di = \dfrac{1}{2} L I^2$. This energy is stored in the magnetic field of the inductor.
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