GATE EE 2022: Electrical Machines Quiz 22 (App update required to attempt this test)
Attempt now to get your rank among 181 students!
The power input to a 3-phase induction motor is 60 kW. Total stator losses are 1000 W, the % efficiency of the motor if it is running at a slip of 4% is. (Assume negligible mechanical losses)
A 3-ϕ, 4-pole 50 Hz slip ring IM has 420 stator turns. The magnitude of the rotating flux per pole is 30 mWb. The winding factors for both stator and rotor windings is 0.96. The magnitude of per phase stator emf is_____V.
A ‘P’ pole, 50 Hz alternator is driven by a 60 Hz synchronous motor. Calculate the number of poles for the synchronous motor.
Consider following parameters:
1. Commutator speed of rotation = 800 rpm
2. Commutator diameter = 0.5 m
3. Width of Brush = 1.5 cm
Then time of commutator is a × 10–3 sec. Then the value of ‘a’ is
For a DC shunt generator at 800 rpm critical field resistance of 200 Ω. Now speed increased by 200 rpm. Change in critical field resistance is
In a single-phase transformer, the total iron loss is 2500 W at nominal voltage of 440 V and frequency 50 Hz. The total iron loss is 850 W at 220 V and 25 Hz. Then, at nominal voltage and frequency, the hysteresis loss and eddy current loss respectively are: