A 4 pole, 250 V, DC series motor has a wave-connected armature with 200 conductors. The flux per pole is 25 mWb when the motor is drawing 60 A from the supply. The armature resistance is 0.15 Ω while the series field winding resistance is 0.2 Ω. Calculate the speed under this condition

Q. A 4 pole, 250 V, DC series motor has a wave-connected armature with 200 conductors. The flux per pole is 25 mWb when the motor is drawing 60 A from the supply. The armature resistance is 0.15 Ω while the series field winding resistance is 0.2 Ω. Calculate the speed under this condition.

A.            1500 RPM

B.            1470 RPM

C.            1300 RPM

D.            1374 RPM

Answer: 1374 RPM