Concept:The power supplied to an inductor and the energy stored in it both depend on the inductance and the current flowing through it.
Explanation:For an inductor, the instantaneous power is given by
P=LidtdiBoth coils have the same constant rate of increase of current, so their
dtdi values are equal.
Since the power dissipated in both coils is the same,
L1i1dtdi=L2i2dtdiCancelling
dtdi from both sides,
L1i1=L2i2Therefore,
i2i1=L1L2The energy stored in an inductor is
U=21Li2Hence, the ratio of stored energies is
U2U1=L2i22L1i12Substituting the current ratio,
U2U1=L2L1(L1L2)2=L1L2Answer:U2U1=L1L2Therefore, the correct option is D,
L1L2.