Q. Explain working of Resistance-capacitance coupled Amplifiers?

Resistance-capacitance (RC)-coupled  Amplifiers : The following figure illustrates the most widely used method for coupling between audio stages.  The bias for each stage is furnished by cathode voltage.  The coupling capacitor, Cc, provides an ac path from the plate of the first stage to the grid of the following stage but blocks any dc voltage.  The load resistor, RL, has a large value so that a large voltage change can be coupled to the grid of the next stage.  When a signal is applied to the first stage, voltage variations occur across RL. These voltage variations are then coupled through the RC circuits, Cc and Rg, to the grid of the second tube.  The coupling capacitor, therefore, performs the double function of providing a low-impedance ac path and of blocking dc plate voltage from the grid of the second tube.