The $$h$$ $$-$$ parameters for a two $$-$$ port network are defined by
$$\left[ {\matrix{ {{E_1}} \cr {{{\rm I}_2}} \cr } } \right] = \left[ {\matrix{ {{h_{11}}} & {{h_{12}}} \cr {{h_{21}}} & {{h_{22}}} \cr } } \right]\left[ {\matrix{ {{{\rm I}_1}} \cr {{E_2}} \cr } } \right].$$
For the two $$-$$ port network shown in Fig. the value of $${h_{12}}$$ is given by

A balanced delta connected load of $$\left( {8 + j6} \right)$$ $$\Omega $$ per phase is connected to a $$400V,$$ $$50Hz,$$ $$3-$$ phase supply lines. If the input power factor is to be improved to $$0.9$$ by connecting a bank of star connected capacitors, the required $$kV$$ $$AR$$ of the bank is

In the circuit of Fig. the magnitudes of $${V_L}$$ and $${V_C}$$ are twice that of $${V_R}$$. The inductance of the coil is

In the circuit shown in Fig., the switch $$S$$ is closed at time $$t=0$$. The voltage across the inductance at $$t = {0^ + },$$ is