1
GATE EE 2009
MCQ (Single Correct Answer)
+2
-0.6
The circuit diagram shows a two-winding, lossless transformer with no leakage flux, excited from a current source, $$i(t)$$, whose waveform is also shown. The transformer has a magnetizing inductance of $$400/\pi \,\,mH.$$ GATE EE 2009 Electrical Machines - Transformers Question 20 English 1 GATE EE 2009 Electrical Machines - Transformers Question 20 English 2

The peak voltage across $$A$$ and $$B$$, with $$S$$ open is

A
$${{400} \over \pi }V$$
B
$$800$$ $$V$$
C
$${{4000} \over \pi }V$$
D
$${{800} \over \pi }V$$
2
GATE EE 2009
MCQ (Single Correct Answer)
+2
-0.6
GATE EE 2009 Electrical Machines - Transformers Question 22 English

The star-delta transformer shown above is excited on the star side with balanced, $$4$$-wire, $$3$$-phase, sinusoidal voltage supply of rated magnitude. The transformer is under no load condition.

With $$S2$$ closed and $$S1$$ open, the current waveform in the delta winding will be

A
a sinusoidal at fundamental frequency
B
flat-topped with third harmonic
C
only third-harmonic
D
none of these
3
GATE EE 2009
MCQ (Single Correct Answer)
+1
-0.3
The single phase, $$50$$ $$Hz$$ iron core transformer in the circuit has both the vertical arms of cross sectional area $$20\,\,c{m^2}$$ and both the horizontal arms of cross sectional area $$10\,\,c{m^2}$$. If the two windings shown were wound instead on opposite horizontal arms, the mutual inductances will GATE EE 2009 Electrical Machines - Transformers Question 34 English
A
double
B
remain same
C
be halved
D
become one quarter
4
GATE EE 2009
MCQ (Single Correct Answer)
+2
-0.6
GATE EE 2009 Electrical Machines - Transformers Question 23 English

The star-delta transformer shown above is excited on the star side with balanced, $$4$$-wire, $$3$$-phase, sinusoidal voltage supply of rated magnitude. The transformer is under no load condition.

With both $$S1$$ and $$S2$$ open, the core flux waveform will be

A
a sinusoidal at fundamental frequency
B
flat-topped with third harmonic
C
peaky with third-harmonic
D
none of these