The two-port Darlington impedance booster of figure uses identical transistors $$({h_{ie}} = 1\,k,\,\,{h_{fe}} = \,100,\,\,{h_{re}} = \,\,{h_{oe}} = \,0$$. Calculate the z-parameters of the network. (Use relavant approximations)

Of the four networks, N₁,N₂, N₃ and N₄ of figure, the networks having identical driving point functions are

For a 2-port network to be reciprocal

Relative to a given fixed tree of a network