If each branch of a Delta circuit has impedance $$\sqrt 3 \,Z$$, then each branch of the equivalent Wye circuit has impedance

A 2-port network is shown in figure. The parameter $${h_{21}}$$ for this network can be given by

The short-circuit admittance matrix of a two-port network is $$$\begin{bmatrix}0&-\frac12\\\frac12&0\end{bmatrix}$$$ The two port network is

The condition, that a 2-port network is reciprocal, can be expressed in terms of its ABCD parameters as ...............