1
GATE EE 2004
MCQ (Single Correct Answer)
+2
-0.6
Two $$3$$-phase, $$Y$$-connected alternators are to be paralleled to a set of common bus bars. The armature has a per phase synchronous reactance of $$1.7\Omega $$ and negligible armature resistance. The line voltage of the first machines is adjusted to $$3300$$ $$V$$ and that of the second machine is adjusted to $$3200$$ $$V.$$ the machine voltages are in phase at the instant they are paralleled. Under this condition, the synchronizing current per phase will be
A
$$16.98A$$
B
$$29.41A$$
C
$$33.96A$$
D
$$58.82A$$
2
GATE EE 2004
MCQ (Single Correct Answer)
+1
-0.3
The following motor definitely has a permanent magnet rotor
A
DC commutator motor
B
Brushless dc motor
C
Stepper motor
D
Reluctance motor
3
GATE EE 2004
MCQ (Single Correct Answer)
+2
-0.6
A single-phase, 230 V, 50 Hz, 4 pole, capacitor-start induction motor has the following stand still impedances
Main winding Zm =6.0 + j4.0Ω
Auxiliary winding Za = 8.0 + j6.0Ω
The value of the starting capacitor required to produce 90° phase difference between the currents in the main and auxiliary windings will be
A
176.84 µF
B
187.24 µF
C
265.26 µF
D
280.86 µF
4
GATE EE 2004
MCQ (Single Correct Answer)
+2
-0.6
A rotating electrical machine having its self-inductances of both the stator and the rotor windings, independent of the rotor position will be definitely not develop
A
starting torque
B
synchronizing torque
C
hysteresis torque
D
reluctance torque