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)

Which of the following signals is/are periodic?

If G(f) represents the Fourier transform of a signal g (t) which is real and odd symmetric in time, then

A linear discrete - time system has the characteristic equation, $${z^3} - 0.81\,\,z = 0.$$ The system