Answer
See explanation.
Work Step by Step
a. $U=\frac{1}{2}LI^2=\frac{1}{2}(12.0H)(0.500A)^2=1.50J$.
b. $P=I^2R=(0.500A)^2(180\Omega)=45.0W$
c. No. the stored energy depends on the current, which is constant. The energy being dissipated by the inductor comes from the emf source (e.g., battery) that drives the current.
