The ratio of enthalpy drop in rotor or moving blade to the enthalpy drop in the stage is called degree of reaction. In a stage, pressure and enthalpy drop occurs both in the fixed blade or stator or nozzle and in the moving blade. The enthalpy drop per stage of one row fixed and one row moving blades is divided among them. For example, a blade with a 50 percent degree of reaction, or a 50 percent reaction stage, is one in which half the enthalpy drop of the stage occurs in the fixed blades and half in the moving blades. The pressure drops will not be equal, however. Here, degree of reaction will be → R = Enthalpy drop in moving blades / enthalpy drop across the stage Enthalpy drop across moving blades = Enthalpy drop across stage – Enthalpy drop in fixed blades =20−8=12 So, R=12×