A 220-V d.c. machine has an armature resistance of 1.0 Ω. If the full-load armature current is 10 A, find the induced e.m.f. when the machine acts as (a) generator (b) motor. (Assume d.c. machine to be shunt connected and in each case it is considered negligible)
1
220 V, 240 V
2
230 V, 210 V
3
220 V, 200 V
4
230 V, 220 V