Of a shunt excited DC generator, Excitation winding internal resistance Rf = 2.5 0 Armature winding internal resistance Ra = 0.5 Q www A rheostat has been placed in the excitation circuit to keep the end voltage of the machine constant at Va = 30 V. Machine Voltage magnetization induced in the armature while operating at n = 1400 rpm at If = 7 A excitation current %3D It is determined as Ea = 37 V from its characteristic. According to this, a) With peak voltage Va = 30 V, excitation current If = 7 A, power supplied to the load when the speed n = 1400 rpm What is the resistance of the rheostat? b) Spindle revolutions are reduced to n = 1000 rpm. In this case Va = 30 V and Ea = 37 V constant What value should the rheostat be adjusted to keep it? Calculate the power given to the load in this new case. w w