1
GATE EE 2021
MCQ (Single Correct Answer)
+1
-0.33

Two generators have cost functions $F_1$ and $F_2$. Their incremental-cost characteristics are

$$ \frac{d F_1}{d P_1}=40+0.2 P_1 \text { and } \frac{d F_2}{d P_2}=32+0.4 P_2 $$

They need to deliver a combined load of 260 MW . Ignoring the network losses, for economic operation, the generations $P_1$ and $P_2$ (in MW) are

A

$P_1=P_2=130$

B

$P_1=160, P_2=100$

C

$P_1=140, P_2=120$

D

$P_1=120, P_2=140$

2
GATE EE 2021
MCQ (Single Correct Answer)
+2
-0.67

A 3-bus network is shown. Consider generators as ideal voltage sources. If rows 1,2 and 3 of the $Y_{h s}$ matrix correspond to bus 1,2 and 3 respectively, then $Y_{h s}$ of the network is

GATE EE 2021 Power System Analysis - Load Flow Studies Question 3 English
A

$\left[\begin{array}{ccc}-4 j & j & j \\ j & -4 j & j \\ j & j & -4 j\end{array}\right]$

B

$\left[\begin{array}{ccc}-4 j & 2 j & 2 j \\ 2 j & -4 j & 2 j \\ 2 j & 2 j & -4 j\end{array}\right]$

C

$\left[\begin{array}{ccc}-\frac{3}{4} j & \frac{1}{4} j & \frac{1}{4} j \\ \frac{1}{4} j & -\frac{3}{4} j & \frac{1}{4} j \\ \frac{1}{4} j & \frac{1}{4} j & \frac{-3}{4} j\end{array}\right]$

D

$\left[\begin{array}{ccc}\frac{-1}{2} j & \frac{1}{4} j & \frac{1}{4} j \\ \frac{1}{4} j & -\frac{1}{2} j & \frac{1}{4} j \\ \frac{1}{4} j & \frac{1}{4} j & \frac{-1}{2} j\end{array}\right]$

3
GATE EE 2021
MCQ (Single Correct Answer)
+2
-0.67

In the figure shown, self-impedances of the two transmission lines are $1.5 j \mathrm{pu}$ each and $Z_m=0.5 j \mathrm{pu}$ is the mutual impedance. Bus voltages shown in the figure are in pu. Given that $\delta>0$, the maximum steady state real power that can be transferred in pu from bus- 1 to bus- 2 is

GATE EE 2021 Power System Analysis - Parameters and Performance of Transmission Lines Question 2 English
A

$|E||V|$

B

$\frac{|E||V|}{2}$

C

$2|E||V|$

D

$\frac{3|E||V|}{2}$

4
GATE EE 2021
MCQ (Single Correct Answer)
+1
-0.33

Consider a power system consisting of $N$ number of buses. Buses in this power system are categorized into slack bus. $P V$ buses and $P Q$ buses for load flow study. The number of $P Q$ buses is $N_L$. The balanced Newton-Raphson method is used to carry out load flow study in polar form $H, S, M$ and $R$ are sub-matrices of the Jacobian matrix $J$ as shown below:

$$ \left[\begin{array}{l} \Delta P \\ \Delta Q \end{array}\right]=J\left[\begin{array}{l} \Delta \delta \\ \Delta \gamma \end{array}\right] \text {, where } J=\left[\begin{array}{ll} H & S \\ M & R \end{array}\right] $$

The dimension of the sub matrix $M$ is

A

$N_L \times(N-1)$

B

$(N-1) \times\left(N-1-N_L\right)$

C

$N_L \times\left(N-1+N_L\right)$

D

$(N-1) \times\left(N-1+N_L\right)$