1
GATE EE 2026
MCQ (Single Correct Answer)
+1
-0

The initial three-phase voltage phasors ( $\vec{V}_A, \vec{V}_B$, and $\vec{V}_C$ ) at a bus of a power network are as shown in Case-1. Due to a disturbance, the bus voltage phasors changed in phase by a small angle $\Delta \theta$, and the magnitudes remained the same as depicted in Case- 2 .

GATE EE 2026 Power System Analysis - Symmetrical Components and Symmetrical and Unsymmetrical Faults Question 2 EnglishWhich one of the following statements is correct about the zero sequence components?

A

The zero sequence components in Case-1 and Case-2 have the same phase angle and magnitude

B

The magnitude of the zero sequence component in Case-1 is greater than that in Case-2

C

The magnitude of the zero sequence component in Case-2 is greater than that in Case-1

D

The zero sequence components in Case-1 and Case-2 have the same magnitude but different phase angles.

2
GATE EE 2026
MCQ (Single Correct Answer)
+2
-0

In the circuit shown, the phase currents are

$$ \begin{aligned} & I_A=572.812+j 50.115 \mathrm{~A} \\ & I_B=-254.525-j 459.175 \mathrm{~A} \\ & I_C=-207.083+j 444.091 \mathrm{~A} \end{aligned} $$

GATE EE 2026 Power System Analysis - Symmetrical Components and Symmetrical and Unsymmetrical Faults Question 1 English

Given that the CTs are ideal with no saturation, and the turns ratio of the Main CT is $300: 5$ and that of the Auxiliary Transformer $(Y n \Delta)$ is $2: 1$ on every phase, the value of $I_{A R}$, rounded off to three decimal places, is

A

0 A

B

$0.653 \angle 17.556^{\circ} \mathrm{A}$

C

$537.24 \angle 4.105^{\circ} \mathrm{A}$

D

$8.954 \angle 4.105^{\circ} \mathrm{A}$

3
GATE EE 2026
MCQ (Single Correct Answer)
+2
-0

The operating characteristic of a reactance relay is given by $X \leq 1 \Omega$, where $X$ is the reactance calculated by the relay. Its operating characteristic in the admittance plane (G-B plane, where G and B denote conductance and sustenance, respectively, expressed in $\mho$ ) is given by:

A

$G^2+(B+0.5)^2 \geq \frac{1}{4}$

B

$B \geq 1$

C

$(G-1)^2+(B)^2 \leq \frac{1}{2}$

D

$(G)^2+(B-1)^2 \geq \frac{1}{2}$

4
GATE EE 2026
MCQ (Single Correct Answer)
+2
-0
A three-phase two-winding transformer has a voltage transformation ratio $\frac{V_P}{V_S}=0.866+j 0.5$, where $V_P$ is the primary side voltage in p.u., and $V_S$ is the secondary side voltage in p.u. $I_P$ and $I_S$ represent the currents injected into the primary and secondary sides of the transformer, respectively. The admittance corresponding to the leakage impedance of the transformer referred to the secondary is $y_t$, p.u. Neglect the magnetizing branch.GATE EE 2026 Power System Analysis - Load Flow Studies Question 1 English The $Y$ bus representation of this transformation is
A

$\left[\begin{array}{c}I_P \\ I_S\end{array}\right]=\left[\begin{array}{cc}\frac{y_t}{0.866+j 0.5} & \frac{y_t}{0.866+j 0.5} \\ -\frac{y_t}{0.866+j 0.5} & \frac{y_t}{0.866+j 0.5}\end{array}\right]\left[\begin{array}{l}V_P \\ V_S\end{array}\right]$

B

$\left[\begin{array}{l}I_P \\ I_S\end{array}\right]=\left[\begin{array}{cc}y_t & -y_t \\ -y_t & y_t\end{array}\right]\left[\begin{array}{l}V_P \\ V_S\end{array}\right]$

C

$\left[\begin{array}{c}I_P \\ I_S\end{array}\right]=\left[\begin{array}{cc}y_t & -\frac{y_t}{0.866+j 0.5} \\ -\frac{y_t}{0.866+j 0.5} & y_t\end{array}\right]\left[\begin{array}{l}V_P \\ V_S\end{array}\right]$

D

$\left[\begin{array}{c}I_P \\ I_S\end{array}\right]=\left[\begin{array}{cc}y_t & -\frac{y_t}{0.866-j 0.5} \\ -\frac{y_t}{0.866+j 0.5} & y_t\end{array}\right]\left[\begin{array}{l}V_P \\ V_S\end{array}\right]$