MCQOPTIONS
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MCQOPTIONS
This section includes 12 Mcqs, each offering curated multiple-choice questions to sharpen your Power Systems knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A 10-bus power system consists of four generator buses indexed as G1, G2, G3, G4 and six load buses indexed as L1, L2, L3, L4, L5, L6. The generator-bus G1 is considered as slack bus, and the load buses L3 and L4 are voltage-controlled buses. The generator at bus G2 cannot supply the required reactive power demand, and hence it is operating at its maximum reactive power limit. The number of non-linear equations required for solving the load flow problem using Newton-Raphson method in polar form is ___________. |
| A. | 4 |
| B. | 24 |
| C. | 20 |
| D. | 14 |
| Answer» E. | |
| 2. |
For a 15-bus system power system with 3 voltage-controlled buses, the size of Jacobian matrix of Newton-Raphson method used to solve load flow problem is: |
| A. | 25 × 25 |
| B. | 12 × 12 |
| C. | 24 × 24 |
| D. | 11 × 11 |
| Answer» B. 12 × 12 | |
| 3. |
Compared to Gauss-Seidel method, Newton-Raphson method takes |
| A. | less number of iterations and more time per iteration |
| B. | less number of iterations and less time per iteration |
| C. | more number of iterations and more time per iteration |
| D. | more number of iterations and less time per iteration |
| Answer» B. less number of iterations and less time per iteration | |
| 4. |
In Gauss-Seidel’s method of power flow solution, the acceleration factor is used for |
| A. | Reducing the number of iterations |
| B. | Increasing the number of iterations |
| C. | One step solution in one iteration |
| D. | Easy back substitution of voltages |
| Answer» B. Increasing the number of iterations | |
| 5. |
Generally in load flow analysis, the load is modelled as a |
| A. | constant impedance load |
| B. | constant power load |
| C. | constant current load |
| D. | dynamically varying load |
| Answer» C. constant current load | |
| 6. |
α (Alpha) in G-S load flow method is used: |
| A. | To enhance rate of convergence |
| B. | To enhance the stability limit |
| C. | To decrease the voltage values of the bus bar |
| D. | To count the iteration number |
| Answer» B. To enhance the stability limit | |
| 7. |
A 1000 × 1000 bus admittance matrix for an electric power system has 8000 non-zero elements. The minimum number of branches (transmission lines and transformers) in this system are: |
| A. | 1000 |
| B. | 2000 |
| C. | 106 |
| D. | 3500 |
| Answer» E. | |
| 8. |
In a power system, there are 50 buses as follows:Slack bus = 1Generator buses = 8Load buses = 41By the Newton-Raphson method, the size of the Jacobian matrix is: |
| A. | 80 × 80 |
| B. | 70 × 70 |
| C. | 60 × 60 |
| D. | 90 × 90 |
| Answer» E. | |
| 9. |
In Gauss-Sidel load flow method, the number of iterations may be reduced if the correction in voltage at each bus is multiplied by, |
| A. | Gauss constant |
| B. | Acceleration factor |
| C. | Blocking factor |
| D. | Lagrange multiplier |
| Answer» C. Blocking factor | |
| 10. |
A 3-Bus network is shown. Consider generators as ideal voltage sources. If rows 1, 2 and 3 of the YBus matrix correspond to Bus 1, 2 and 3, respectively, then YBus of the network is |
| A. | \(\left[ \begin{array}{20 {c*}} {-\frac 3 4 j}&{\frac 1 4 j}&{\frac 1 4 j}\\\ {\frac 1 4 j}&{-\frac 3 4 j}&{\frac 1 4j}\\\ {\frac 1 4 j}&{\frac 1 4 j}&{-\frac 3 4 j} \end{array} \right]\) |
| B. | \(\left[ \begin{array}{20 {c*}} {-4j}&{2j}&{2j}\\\ {2j}&{-4j}&{2j}\\\ {2j}&{2j}&{-4j} \end{array} \right]\) |
| C. | \(\left[ \begin{array}{20 {c*}} {-\frac 1 2j}&{\frac 1 4j}&{\frac 1 4j}\\\ {\frac 1 4j}&{-\frac 1 2j}&{\frac 1 4j}\\\ {\frac 1 4j}&{\frac 1 4j}&{-\frac 1 2j} \end{array} \right]\) |
| D. | \(\left[ \begin{array}{20 {c*}} {-4j}&{j}&{j}\\\ {j}&{-4j}&{j}\\\ {j}&{j}&{-4j} \end{array} \right]\) |
| Answer» B. \(\left[ \begin{array}{20 {c*}} {-4j}&{2j}&{2j}\\\ {2j}&{-4j}&{2j}\\\ {2j}&{2j}&{-4j} \end{array} \right]\) | |
| 11. |
If a voltage controlled bus is treated as a load bus, then which one of the following limits would be violated? |
| A. | Voltage |
| B. | Active power |
| C. | Reactive power |
| D. | Phase angle |
| Answer» D. Phase angle | |
| 12. |
For the slack bus in load flow study |
| A. | Voltage magnitude and reactive power are specified. |
| B. | Active and reactive power are specified. |
| C. | Voltage magnitude and phase angle are specified. |
| D. | Active power and phase angle are specified. |
| Answer» D. Active power and phase angle are specified. | |