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In a coil, the current changes from -2 A to +2 A in 0.2 s and induces an emf of 0.1 V. The self inductance of the coil is :
(4) 5 mH
| | = L I t, with I = 2 - (-2) = 4 A
0.1 = L 40.2 = 20L
L = 0.120 = 5 10-3 H = 5 mH
Answer: (4)
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