Two identical triode tubes are connected in parallel, as shown in the figure. The anodes are joined together, the grids are joined together, and the cathodes are joined together. Assuming each tube possesses a plate resistance r_p , a mutual conductance g_m , and an amplification factor , find the equivalent plate resistance, equivalent mutual conductance, and equivalent amplification factor of the parallel combinati

Step-by-step solution

For a single triode, the small change in plate current i_p is given by: i_p = g_m v_g + 1 r_p v_p When two identical triodes are connected in parallel, their grids, plates, and cathodes are joined together. Therefore, they share the same grid voltage change v_g and plate voltage change v_p . The total plate current change i_ p,eq is the sum of the individual plate current changes: i_ p,eq = i_ p1 + i_ p2 Since the triodes are identical, substituting the expressions gives: i_ p,eq = 2 ( g_m v_g + 1 r_p v_p ) i_ p,eq