Question

In the circuit shown in the figure, what is the value of ${{I}_{1}}$ just after pressing the key K?5/7 A5/11 A1 ANone of these

Hint: First trace the path through which the current is going to pass, now after tracing the path find the equivalent resistance or capacitance if required. Then calculate the value of current flowing through the circuit.

In the above diagram when the key K is closed, we see that a potential difference of 10V and a current has been induced in the circuit, now when the current tries to pass through the 2mH inductor, it could not pass because of its excessively high resistance, so the current takes the path 1, shown in the diagram.
Now in path 1,
Equivalent resistance,
${{R}_{eq}}=\left( 6+8 \right)\Omega$ ,
${{R}_{eq}}=14\Omega$,
So the value of current ${{I}_{1}}$ flowing through the circuit is,
${{I}_{1}}=\dfrac{V}{{{R}_{eq}}}$,
${{I}_{1}}=\dfrac{10}{14}$,
${{I}_{1}}=\dfrac{5}{7}A$,

Therefore the correct option is, option A which is (5/7 A).