A 220 V DC machine has an armature resistance of 0.5 Ω. If the full load armature current is 20 A, the induced EMF when the machine is working as generator and motor are, respectively:
1
210 V and 230 V
2
220 V and 240 V
3
240 V and 220 V
4
250 V and 230 V
5
230 V and 210 V