Electrical Machines
Induction Machines
Marks 1Marks 2
Synchronous Machines
Marks 1Marks 2Marks 5
1
GATE EE 2015 Set 2
MCQ (Single Correct Answer)
+2
-0.6
A three-winding transformer is connected to an AC voltage source as shown in the figure. The number of turns are as follows: N1=100, N2=50, N3=50. If the magnetizing current is neglected, and the currents in two windings are $${\overline I}_2=2\angle30^\circ$$ A and $${\overline I}_3=2\angle30^\circ$$ A, then what is the value of the current $${\overline I}_1$$ in Ampere? GATE EE 2015 Set 2 Electrical Machines - Transformers Question 68 English
A
$$1\angle90^\circ$$
B
$$1\angle270^\circ$$
C
$$4\angle90^\circ$$
D
$$4\angle270^\circ$$
2
GATE EE 2014 Set 2
MCQ (Single Correct Answer)
+2
-0.6
For a single phase, two winding transformer, the supply frequency and voltage are both increased by 10%. The percentage changes in the hysteresis loss and eddy current loss, respectively are
A
10 and 21
B
-10 and 21
C
21 and 10
D
-21 and 10
3
GATE EE 2014 Set 3
Numerical
+2
-0
The load shown in the figure absorbs 4 kW at a power factor of 0.89 lagging. GATE EE 2014 Set 3 Electrical Machines - Transformers Question 64 English Assuming the transformer to be ideal, the value of the reactance X to improve the input power factor to unity is ___________.
Your input ____
4
GATE EE 2014 Set 3
MCQ (Single Correct Answer)
+2
-0.6
An open circuit test is performed on 50 Hz transformer, using variable frequency source and keeping V/f ratio constant, to separate its eddy current and hysteresis losses. The variation of core loss/frequency as function of frequency is shown in the figure GATE EE 2014 Set 3 Electrical Machines - Transformers Question 63 English The hysteresis and eddy current losses of the transformer at 25 Hz respectively are
A
250 W and 2.5 W
B
250 W and 62.5 W
C
312.5 W and 62.5 W
D
312.5 W and 250 W
GATE EE Subjects
Electromagnetic Fields
Signals and Systems
Engineering Mathematics
General Aptitude
Power Electronics
Power System Analysis
Analog Electronics
Control Systems
Digital Electronics
Electrical Machines
Electric Circuits
Electrical and Electronics Measurement