A 250 V DC shunt motor runs at 1,000 rpm and takes 6 A at no-load. The armature resistance of the motor is 0.04 Ω and shunt field resistance is 250 Ω. Calculate the change in speed when the motor is...

A 250 V DC shunt motor runs at 1,000 rpm and takes 6 A at no-load. The armature resistance of the motor is 0.04 Ω and shunt field resistance is 250 Ω. Calculate the change in speed when the motor is loaded and takes 51 A from the lines. Neglect armature reaction.