An inductor used in a dc power supply has an inductance of 12 H and a resistance of 180 ohms and carries a current of .300 A. (a) How much energy is stored in the magnetic field? (b) At what rate is thermal energy developed in the inductor?

ok once again I got part (a) .540 J, but I am confused on part (b) again! Help please!

ok once again I got part (a) .540 J, but I am confused on part (b) again! Help please!