The equivalent of the block diagram in Figure is given as

An electrical system and its signal-flow graph representations are shown in Figure (a) and (b) respectively. The values of G₂ and H, respectively are

The feedback control system in Figure is stable

Consider the feedback control system shown in figure.
(a) Find the transfer function of the system and its characteristic equation.

(b) Use the Routh-Hurwitz criterion to determine the range of 'K' for which the system is stable.