In the given circuit, the voltage $$\overline {{V_L}} $$ has a phase angle of ____________ with respect to $$\overline {{V_S}} .$$

A set of $$3$$ equal resistors, each of value $${R_X},$$ connected in star across $$RYB$$ of given Fig. consumes the same power as the unbalanced delta-connected load shown. The value of $${R_X}$$ is _____________ $$\Omega .$$

If a two-port network is passive, then we have, with the usual notation, the following relationship

Superposition principle is not applicable to a network containing time-varying registors.