What is mutual conductance of triode?

Mutual conductance, often denoted as ( g_m ), is a key parameter in triodes that measures the change in the plate current (( I_p )) relative to the change in the grid voltage (( V_g )), while keeping other voltages constant. It is defined as ( g_m = \frac{dI_p}{dV_g} ). This parameter indicates the amplification capability of the triode; a higher mutual conductance signifies greater sensitivity of the plate current to variations in the grid voltage, resulting in increased amplification. Mutual conductance is typically expressed in units of siemens (S).