1

GATE EE 2006

MCQ (Single Correct Answer)

+2

-0.6

For a power system the admittance and impedance matrices for the fault studies are as follows.
$$$\eqalign{
& {Y_{bus}} = \left[ {\matrix{
{ - j8.75} & {j1.25} & {j2.50} \cr
{j1.25} & { - j6.25} & {j2.50} \cr
{j2.50} & {j2.50} & { - j5.00} \cr
} } \right] \cr
& {Z_{bus}} = \left[ {\matrix{
{j0.16} & {j0.08} & {j0.12} \cr
{j0.08} & {j0.24} & {j0.16} \cr
{j0.12} & {j0.16} & {j0.34} \cr
} } \right] \cr} $$$

The pre-fault voltages are $$1.0$$ $$p.u.$$ at all the buses. The system was unloaded prior to the fault. A solid $$3$$ phase fault takes place at bus $$2.$$

The per unit fault feeds from generators connected to buses $$1$$ and $$2$$ respectively are

2

GATE EE 2005

MCQ (Single Correct Answer)

+2

-0.6

The network shown in the given figure has impedances in p.u. as indicated. The diagonal element $$Y22$$ of the bus admittance matrix $${Y_{BUS}}$$ of the network is

3

GATE EE 2003

MCQ (Single Correct Answer)

+2

-0.6

The bus impedance matrix of a $$4$$-bus power system is given by
$$${Z_{bus}} = \left[ {\matrix{
{j0.3435} & {j0.2860} & {j0.2723} & {j0.277} \cr
{j0.2860} & {j0.3408} & {j0.2586} & {j0.2414} \cr
{j0.2723} & {j0.2586} & {j0.2791} & {j0.2209} \cr
{j0.2277} & {j0.2414} & {j0.2209} & {j0.2791} \cr
} } \right]$$$

A branch having an impedance of $$j0.2\Omega $$ is connected between bus $$2$$ and the reference. Then the values of $${Z_{22,new}}$$ and $${Z_{23,new}}$$ of the bus impedance matrix of the modified network are respectively

4

GATE EE 2002

MCQ (Single Correct Answer)

+2

-0.6

A power system consists of 2 areas (Area 1 and Area 2) connected by a single tie line (figure). It is required to carry out a load flow study on this system. While entering the network data, the tie-line data (connectivity and parameters) is inadvertently left out. If the load flow program is run with this incomplete data.

Questions Asked from Load Flow Studies (Marks 2)

Number in Brackets after Paper Indicates No. of Questions

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