A 500 V shunt motor runs at its normal speed of 10 rev/s when the armature current is 120 A. The armature resistance is 0.252. (a) Determine the speed when the current is 60 A and a resistance of 0.522 is connected in series with the armature, the shunt field remaining constant. (b) Determine the speed when the current is 60 A and the shunt field is reduced to 80% of its normal value by increasing resistance in the field circuit.