Two inductors of $60 \mathrm{mH}$ each are joined in parallel. The current passing through this combination…

Two inductors of $60 \mathrm{mH}$ each are joined in parallel. The current passing through this combination is $2.2 \mathrm{~A}$. The energy stored in this combination of inductors in joule is
  1. $0.0333$
  2. $0.0667$
  3. $0.0726$
  4. $0.0984$

Solution

$\mathrm{L}_1=\mathrm{L}_2=\mathrm{L}=60 \mathrm{mH}$ When two inductors are connected in parallel, their equivalent inductance is given by, $\begin{aligned} & \frac{1}{\mathrm{~L}_{\text {eq }}}=\frac{1}{\mathrm{~L}_1}+\frac{1}{\mathrm{~L}_2} \\ & \therefore \quad \mathrm{L}_{\mathrm{eq}}=\frac{\mathrm{L}}{2}=30 \mathrm{mH} \\ & \mathrm{u}_{\mathrm{B}}=\frac{1}{2} \mathrm{~L}_{\mathrm{eq}} \mathrm{I}^2 \\ & \therefore \quad \mathrm{u}_{\mathrm{B}}=\frac{1}{2} \times 30 \times 10^{-3} \times 2.2 \times 2.2 \\ & \therefore \quad \mathrm{u}_{\mathrm{B}}=0.0726 \mathrm{~J} \\ & \end{aligned}$

Asked in: MHT CET 2023 (12 May Shift 1)

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