1
GATE EE 2009
MCQ (Single Correct Answer)
+2
-0.6
GATE EE 2009 Electrical Machines - Transformers Question 25 English

The figure above shows coil $$1$$ and $$2,$$ with dot markings as shown, having $$4000$$ and $$6000$$ turns respectively. Both the coils have a rated current of $$25$$ $$A.$$ Coil $$1$$ is excited with single phase, $$400$$ $$V,$$ $$50$$ $$Hz$$ supply.

In the auto-transformer obtained in Question $$30,$$ the current in each coil is

A
Coil -$$1$$ is $$25$$ $$A$$ and Coil - $$2$$ is $$10$$ $$A$$
B
Coil -$$1$$ is $$10$$ $$A$$ and Coil - $$2$$ is $$25$$ $$A$$
C
Coil -$$1$$ is $$10$$ $$A$$ and Coil - $$2$$ is $$15$$ $$A$$
D
Coil -$$1$$ is $$15$$ $$A$$ and Coil - $$2$$ is $$10$$ $$A$$
2
GATE EE 2009
MCQ (Single Correct Answer)
+2
-0.6
GATE EE 2009 Electrical Machines - Transformers Question 26 English

The figure above shows coil $$1$$ and $$2,$$ with dot markings as shown, having $$4000$$ and $$6000$$ turns respectively. Both the coils have a rated current of $$25$$ $$A.$$ Coil $$1$$ is excited with single phase, $$400$$ $$V,$$ $$50$$ $$Hz$$ supply.

The coils are to be connected to obtain a single-phase, $${{400} \over {1000}}\,\,V,$$ auto-transformer to drive a load of $$10$$ $$kVA.$$ Which of the options given should be exercised to realize the required auto-transformer?

A
Connect $$A$$ and $$D;$$ Common $$B$$
B
Connect $$B$$ and $$D;$$ Common $$C$$
C
Connect $$A$$ and $$C;$$ Common $$B$$
D
Connect $$A$$ and $$C;$$ Common $$D$$
3
GATE EE 2009
MCQ (Single Correct Answer)
+2
-0.6
$$$F\left(x,y\right)=\left(x^2\;+\;xy\right)\;{\widehat a}_x\;+\;\left(y^2\;+\;xy\right)\;{\widehat a}_y$$$. Its line integral over the straight line from (x, y)=(0,2) to (2,0) evaluates to
A
-8
B
4
C
8
D
$$0$$
4
GATE EE 2009
MCQ (Single Correct Answer)
+1
-0.3
The trace and determinant of a $$2 \times 2$$ matrix are shown to be $$-2$$ and $$-35$$ respectively. Its eigen values are
A
$$-30, -5$$
B
$$-37,-1$$
C
$$-7,5$$
D
$$17.5, -2$$