Consider two coupled circuits having self inductances $L_1$ and $L_2$ that carry non-zero currents $I_1$ and $I_2$ respectively. The mutual inductance between the circuit is $M$ with unity coupling coefficient. The stored magnetic energy of the coupled circuit is minimum at which of the following value(s) of $I_1 / I_2$ ?

In the circuit shown below, the magnitude of the voltage V₁ in volts, across the 8 k$$\Omega$$ resistor is ________. (round off to nearest integer).

In the given circuit, the parameter k is positive, and the power dissipated in the 2 Ω resistor is 12.5 W. The value of k is ________.

The current i (in Ampere) in the 2 Ω resistor of the given network is _________.