A shunt motor rotating at 1500 rpm is fed by a 120V dc source. The line current is 51 A and the shunt-field resistance is 120 ohm. If the armature resistance is 0.1 ohm, calculate armature current and the counter-emf (Ea) and then calculate the speed if the shunt-field resistance is doubled at no load condition. (at no load condition meand armature resistance is 0).
Suppose the terminal voltage VT does not change.