In the circuit shown in the figure, the switch S has been

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In the circuit shown in the figure, the switch S has been opened for long time. It is closed at t = 0. For t > 0, the current flowing through the inductor will be given by

1. i_L (t) = 1.2 + 0.8 e^{– 2t}
2. i_L (t) = 0.8 + 1.2 e^{– 2t}
3. i_L (t) = 1.2 – 0.8 e^{– 2t}
4. i_L (t) = 0.8 – 1.2 e^{– 2t}

Correct Option: A

At the instant of closing the switch, current through the inductor

=	36	= 2 A
	12 + 6

Under steady state conditions after closing of the switch,

current =	36	+	6	=	6	A
	15		12		5

Here the equation which satisfies is
i_L (t) = 1.2 + 0.8 e^{– 2t}