Two inductors of 80 mH each are joined in parallel. The current passing through the combination is 2.1 A .…

Two inductors of 80 mH each are joined in parallel. The current passing through the combination is 2.1 A . The energy stored in this combination of inductors is
  1. $4.84 \times 10^{-2} \mathrm{~J}$
  2. $7.26 \times 10^{-2} \mathrm{~J}$
  3. $8.82 \times 10^{-2} \mathrm{~J}$
  4. $10.85 \times 10^{-2} \mathrm{~J}$

Solution

Energy stored in parallel inductor combination

For two identical inductors $L_1 = L_2 = L = 80 \times 10^{-3}$ H connected in parallel, the equivalent inductance is $L_{eq} = \frac{L}{2} = 40 \times 10^{-3}$ H.

The energy stored in an inductor carrying current $I = 2.1$ A is given by $U = \frac{1}{2} L_{eq} I^2$. Substituting values:

$U = \frac{1}{2} (40 \times 10^{-3}) (2.1)^2 = \frac{1}{2} (40 \times 10^{-3}) (4.41) = 88.2 \times 10^{-3} = 8.82 \times 10^{-2}$ J

This matches option C.

Asked in: MHT CET 2025 (05 May Shift 2)

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