Time Left - 20:00 mins
Champion Test GATE 2019: Electrical Machines
Attempt now to get your rank among 1224 students!
Question 1
A 3 – phase, 4 – pole, 50Hz IM runs at speed of 1440 rpm calculate speed of the rotor field with respect to rotor ________ (fill in the blanks)
Question 2
what is the saving of copper If K is the transformation ratio of step up autotransformer and Wtw is the total weight of copper in two winding transformer?
Question 3
For autotransformer circuit shown in Figure, Assuming V1 = 1250 v and V2 = 800 V. Calculate the currents I1, I2 and Io.
Question 4
In a 3 – phase Induction motor the rotor field rotates at synchronous speed with respect to –
Question 5
If the supply voltage of Induction motor is reduced by 50%, the maximum torque will decrease by –
Question 6
The parameters measured for a 220/110V, 50 Hz, single-phase transformer are:
Self inductance of primary winding = 45 mH
Self inductance of secondary winding = 30 mH
Mutual inductance between primary and secondary windings = 20 mH
Using the above parameters, the leakage L1, L2 and magnetizing
inductances as referred to primary side in the equivalent circuit respectively, are
Self inductance of primary winding = 45 mH
Self inductance of secondary winding = 30 mH
Mutual inductance between primary and secondary windings = 20 mH
Using the above parameters, the leakage L1, L2 and magnetizing
inductances as referred to primary side in the equivalent circuit respectively, are Question 7
A 3-φ, 20 MVA, 13.8 KV, 50 Hz synchronous generator yields the following test data.
OC test field current = 897A at rated voltage
SC test field current = 250A at rated armature current
Calculate its p.u. adjusted synchronous reactance. OC test revealed that the armature
resistance per phase is 0.75 Ω
OC test field current = 897A at rated voltage
SC test field current = 250A at rated armature current
Calculate its p.u. adjusted synchronous reactance. OC test revealed that the armature
resistance per phase is 0.75 Ω
Question 8
The emf induced in a conductor of machine driven at 600 rpm, the peak value of flux density is 1 Wb/m2, diameter of machine 2 m and length of machine 0.3 m is ______ V.
Question 9
A 3-phase, 6-pole, 415 V 50 Hz, star connected induction motor has following circuit parameters r1 =1.0Ω, r2'= 0.5Ω, x1=x2 '= 1.2 Ω, Xm= 35Ω.
The starting torque (in %) when the motor is started direct-on-line is (use approximate equivalent circuit model)
The starting torque (in %) when the motor is started direct-on-line is (use approximate equivalent circuit model)
Question 10
The readings of the instruments in an open-circuit test of a transformer are given below:
Ammeter = 6.8 A
Voltmeter = 155 V
Wattmeter = 342 W
Determine the no-load power factor.
Ammeter = 6.8 A
Voltmeter = 155 V
Wattmeter = 342 W
Determine the no-load power factor.
- 1224 attempts
- 7 upvotes
- 13 comments
Nov 7ESE & GATE EE
