Electrical Machine - I Set 1

DC series motors ✘ AC series motors ✘ DC shunt motors ✘ Low resistance squirrel cage motors ✔ (c) and (d) both ✔

Variable excitation to the field of the motor ✘ Constant excitation to the field of the motor ✘ A.C. excitation to the field of the motor ✘ No excitation to the field of the motor ✔

Armature current ✘ Field current ✘ Speed ✘ Magnetic flux ✔

Separately excited generator ✘ Self-excited generator ✘ All A.C. generators ✘ None of them ✔

It will generate maximum voltage ✘ It will generate maximum power ✘ It will not develop voltage at all ✘ None of these ✔

Their polarities must match ✘ Their phase sequence must match ✘ Their polarities and voltages must match ✘ (b) and (c) both ✔

Constant current ✘ Constant torque ✘ Constant speed ✘ Constant magnetic field ✔

Magnetic field ✘ Armature resistance ✘ Voltage ✘ None of the above ✔

Universal motor ✘ Synchronous Motor ✘ D.C. series motor ✘ D.C. shunt motor ✔

Heat only ✘ Magnetic field only ✘ (a) and (b) ✘ Power only ✔