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JEE Main202125 Feb 2021Morning ShiftPhysicsElectromagnetic InductionActual

A coil of inductance 2   H having negligible resistance is connected to a source of supply whose voltage is given by V = 3 t volt. (where t is in second). If the voltage is applied when t = 0 , then the energy stored in the coil after 4   s in J ,

Correct answer

144

Step-by-step solution

ε = L d I d t 3 ∫ 0 4 t d t = 2 ∫ 0 1 d I 3 2 × 16 = 2 I I = 12 V = 1 2 L I 2 = 1 2 × 2 12 2 = 144   J

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