Electromagnetic Induction - Result Question 21

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21. The magnetic potential energy stored in a certain inductor is $25 mJ$, when the current in the inductor is $60 mA$. This inductor is of inductance

======= ####21. The magnetic potential energy stored in a certain inductor is $25 mJ$, when the current in the inductor is $60 mA$. This inductor is of inductance

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/electromagnetic-induction/electromagnetic-induction—result-question-21.md (a) $0.138 H$

(b) $138.88 H$

(c) $13.89 H$

(d) $1.389 H$

[2018]

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Answer:

Correct Answer: 21. (c)

Solution:

  1. (c) From question energy stored in inductor, $U=25 \times 10^{-3} J$

Current, $I=60 mA$

Energy stored in inductor $U=\frac{1}{2} L I^{2}$

$25 \times 10^{-3}=\frac{1}{2} \times L \times(60 \times 10^{-3})^{2}$

$L=\frac{25 \times 2 \times 10^{6} \times 10^{-3}}{3600}=13.89 Hm$