MCQOPTIONS
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MCQOPTIONS
This section includes 180 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
Zero sequence currents cannot flow in which of the following connections? |
| A. | Delta |
| B. | Star |
| C. | Star – star |
| D. | Both (b) and (c) |
| E. | All of these |
| Answer» B. Star | |
| 102. |
Which of the following fault results into a three phase faults? |
| A. | Single line to ground fault. |
| B. | Double line to ground fault |
| C. | Line to line fault |
| D. | Fault due to all the three phases to earth. |
| Answer» E. | |
| 103. |
Which among theses quantities are to be determined in slack bus? |
| A. | P and Q |
| B. | Q and |V| |
| C. | |V| and δ |
| D. | Q and δ |
| Answer» B. Q and |V| | |
| 104. |
Which among these phenomenons is / are associated with angle stability? |
| A. | Imbalance between the two generator torque |
| B. | Stability or synchronism is lost |
| C. | Surplus energy is stored up in the rotating masses |
| D. | All of these |
| E. | None of these |
| Answer» E. None of these | |
| 105. |
Which among these is the most commonly occurring fault? |
| A. | Single line to ground fault. |
| B. | Double line to ground fault |
| C. | Line to line fault |
| D. | Fault due to all the three phases to earth. |
| Answer» B. Double line to ground fault | |
| 106. |
Which among these is the most severe fault? |
| A. | Single line to ground fault. |
| B. | Double line to ground fault |
| C. | Line to line fault |
| D. | Symmetrical fault. |
| Answer» E. | |
| 107. |
Which among these is the major advantage of per unit computations? |
| A. | Per unit impedance of transformers is the same referred to either side of it. |
| B. | For simulating steady state and transient models in the computer this method is very useful. |
| C. | Manufactures usually specify the impedance of an apparatus in per unit system. |
| D. | All of these |
| Answer» E. | |
| 108. |
Which among these is related to the critical clearing time of a fault in a power system? |
| A. | Transient stability limit |
| B. | Steady state stability limit |
| C. | Frequency limit |
| D. | All of these |
| E. | None of these |
| Answer» B. Steady state stability limit | |
| 109. |
Which among these cannot be determined from equal area criterion? |
| A. | Critical clearing angle |
| B. | Critical clearing time |
| C. | Transient stability limit |
| D. | Both (a) and (b) |
| E. | All of these |
| Answer» C. Transient stability limit | |
| 110. |
Which among the following quantities are to be determined in voltage controlled bus? |
| A. | P and Q |
| B. | Q and |V| |
| C. | |V| and δ |
| D. | Q and δ |
| Answer» E. | |
| 111. |
Which among the following reactance have a greater value? |
| A. | Sub transient reactance |
| B. | Transient reactance |
| C. | Synchronous reactance |
| D. | All of these |
| E. | None of these |
| Answer» D. All of these | |
| 112. |
Which among the following quantities are specified at the generator bus? |
| A. | P and Q |
| B. | P and |V| |
| C. | Q and |V| |
| D. | P and δ |
| Answer» C. Q and |V| | |
| 113. |
Which among the following quantities are specified at the load bus? |
| A. | P and Q |
| B. | P and |V| |
| C. | Q and |V| |
| D. | P and δ |
| Answer» B. P and |V| | |
| 114. |
Which among the following phenomenon is generally associated with voltage stability? |
| A. | Temporary load reduction |
| B. | Voltage is reduced |
| C. | Voltage collapses |
| D. | All of these |
| E. | None of these |
| Answer» E. None of these | |
| 115. |
Which among the following methods are used to improve steady state stability? |
| A. | Reducing the reactance between the transmission and receiving points. |
| B. | By using bundled conductors. |
| C. | By increasing the excitation of generator or motor or both. |
| D. | All of these |
| E. | None of these |
| Answer» E. None of these | |
| 116. |
Which among the following methods are generally used for the calculation of symmetrical faults? |
| A. | Norton theorem |
| B. | Thevnin’s theorem |
| C. | Kirchhoff’s laws |
| D. | Only (b) and (c) |
| E. | All of these |
| Answer» E. All of these | |
| 117. |
Which among the following methods are highly accurate? |
| A. | Gauss Seidel method |
| B. | Newton Raphson method |
| C. | Fast decoupled low flow method |
| D. | All of these |
| E. | None of these |
| Answer» C. Fast decoupled low flow method | |
| 118. |
Which among the following matrix is sparse? |
| A. | Jacobian matrix only |
| B. | Y bus matrix only |
| C. | Z bus matrix only |
| D. | Both (a) and (b) |
| E. | All of these |
| Answer» E. All of these | |
| 119. |
Which among the following is the main assumption to solve a load flow problem by GS method? |
| A. | All the buses are to be considered as PQ bus including the slack bus. |
| B. | All the buses are to be considered as PV bus including the slack bus. |
| C. | All the buses are to be considered as PQ bus excluding the slack bus. |
| D. | All the buses are to be considered as PV bus excluding the slack bus. |
| Answer» D. All the buses are to be considered as PV bus excluding the slack bus. | |
| 120. |
Which among the following is / are used for the solution of load flow using FDLF method? |
| A. | [(Δ P) / E] = [B' ] [Δ δ] |
| B. | [(Δ Q) / E] = [B" ] [ Δ E] |
| C. | [(Δ P) / E] = [B" ] [ Δ δ] |
| D. | Both (a) and (b) |
| E. | All of these |
| Answer» E. All of these | |
| 121. |
Which among the following factors influence the cost of generation of electric power? |
| A. | Generator efficiency |
| B. | Fuel cost |
| C. | Transmission losses |
| D. | All of these |
| E. | None of these |
| Answer» E. None of these | |
| 122. |
Which among the following buses constitute the maximum number in a power system? |
| A. | Slack bus |
| B. | P Q bus |
| C. | P V bus |
| D. | All of these |
| E. | None of these |
| Answer» C. P V bus | |
| 123. |
Which among the following assumptions are made in the reactance diagram? |
| A. | The neutral reactance are neglected |
| B. | Static loads are neglected. |
| C. | The capacitance of the transmission lines are neglected |
| D. | Only a and c |
| E. | All of these |
| Answer» F. | |
| 124. |
What will be the per unit impedance of a synchronous motor having a rating of 100 kVA, 13.2 kV and having a reactance of 75 Ω / ph? |
| A. | 0.043 pu |
| B. | 0.057 pu |
| C. | 0.036 pu |
| D. | 0.298 pu |
| Answer» B. 0.057 pu | |
| 125. |
What will be the penalty factor for a unit, if the generating station is located very close to load centre? |
| A. | Zero |
| B. | Almost equal to unity |
| C. | The penalty factor is negative |
| D. | The value is very high |
| Answer» C. The penalty factor is negative | |
| 126. |
What will be the inertia constant H, for a water wheel generator having a speed less than 200 rpm? |
| A. | 2 - 4 |
| B. | 2 - 3 |
| C. | 1 - 2 |
| D. | 5 - 6 |
| Answer» C. 1 - 2 | |
| 127. |
What will be the multiplying factor if the speed of the circuit breaker is 2 cycles? |
| A. | 2.2 |
| B. | 1.2 |
| C. | 2.8 |
| D. | 1.4 |
| Answer» E. | |
| 128. |
What type of convergence takes place in NR method? |
| A. | Linear convergence |
| B. | Geometric convergence |
| C. | Quadratic convergence |
| D. | All of these |
| E. | None of these |
| Answer» D. All of these | |
| 129. |
What percentage of faults occurring is single line to ground fault? |
| A. | 50 % |
| B. | 60 % |
| C. | 35 % |
| D. | 70 % |
| Answer» E. | |
| 130. |
What percentage of fault occurring in the power system is LLG fault? |
| A. | 20 % |
| B. | 30 % |
| C. | 5 % |
| D. | 10 % |
| Answer» E. | |
| 131. |
What percentage of fault occurring in the power system is line to line fault? |
| A. | 5 % |
| B. | 30 % |
| C. | 25 % |
| D. | 15 % |
| Answer» E. | |
| 132. |
What percentage of buses in the power system are generator buses? |
| A. | 5 % |
| B. | 25 % |
| C. | 70 % |
| D. | 10 % |
| Answer» E. | |
| 133. |
What kind of differential equation is swing equation? |
| A. | Linear second order |
| B. | Non linear first order |
| C. | Linear first order |
| D. | Non linear second order |
| Answer» E. | |
| 134. |
What is voltage stability? |
| A. | To maintain steady voltages at all the buses after the occurrence of fault. |
| B. | To maintain steady voltages at all the buses before the occurrence of fault. |
| C. | To maintain the system frequency after the severe disturbances |
| D. | All of these |
| E. | None of these |
| Answer» B. To maintain steady voltages at all the buses before the occurrence of fault. | |
| 135. |
What is the value of the zero sequence current? |
| A. | 3 times the current in the neutral wire |
| B. | 1 / 3 times the current in the neutral wire |
| C. | √3 times the current in the neutral wire |
| D. | Equal to the current in the neutral wire |
| Answer» C. √3 times the current in the neutral wire | |
| 136. |
What is the value of the letter ‘a’ or ‘α’ which is commonly used in symmetrical components? |
| A. | 1 ∠ 90° |
| B. | 1 ∠ 30° |
| C. | 1 ∠ 120° |
| D. | 1 ∠ -120° |
| Answer» D. 1 ∠ -120° | |
| 137. |
What is the value of negative sequence impedance? |
| A. | 1 |
| B. | Z |
| C. | Same as positive sequence |
| D. | ∞ |
| Answer» D. ∞ | |
| 138. |
What is the value of acceleration factor used in the GS method? |
| A. | 2.3 – 2.7 |
| B. | 1.6 – 2.0 |
| C. | 1.2 – 1.5 |
| D. | 2.4 – 2.9 |
| Answer» C. 1.2 – 1.5 | |
| 139. |
What is the simplified diagram called, after omitting all resistances, static loads, capacitance of the transmission lines and magnetising circuit of the transformer? |
| A. | Single line diagram |
| B. | Resistance diagram |
| C. | Reactance diagram |
| D. | Both (a) and (b) |
| E. | None of these |
| Answer» D. Both (a) and (b) | |
| 140. |
What is the result of frequency instability? |
| A. | Voltage collapse |
| B. | Frequency swings |
| C. | Tripping of generating units |
| D. | Both (b) and (c) |
| E. | All of these |
| Answer» E. All of these | |
| 141. |
What is the rated breaking capacity of the circuit breaker? |
| A. | The product of rated voltage and rated breaking current |
| B. | The product of rated voltage and rated symmetrical breaking current |
| C. | The product of fault voltage and breaking current |
| D. | None of these |
| Answer» C. The product of fault voltage and breaking current | |
| 142. |
What is the range of ‘δ’ for stable operation? |
| A. | 0° < δ < 45° |
| B. | 45° < δ < 90° |
| C. | 0° < δ < 90° |
| D. | 0° < δ < 120° |
| Answer» D. 0° < δ < 120° | |
| 143. |
What is the percentage of occurrence of symmetrical faults? |
| A. | 10 % |
| B. | 15 % |
| C. | 5 % |
| D. | None of these |
| Answer» D. None of these | |
| 144. |
What is the per unit system (PU)? |
| A. | A ratio of actual value in any units to the base or reference value in the same units |
| B. | A ratio of the base or reference value in any units to the actual value in the same units. |
| C. | Ratio of the square of the actual value in any units to the square of base or the reference value in the same units |
| D. | All of these |
| Answer» B. A ratio of the base or reference value in any units to the actual value in the same units. | |
| 145. |
What is the multiplication factor to be multiplied with symmetrical momentary current to account for the presence of DC off set current? |
| A. | 1.2 |
| B. | 1.5 |
| C. | 1.6 |
| D. | 2.5 |
| Answer» D. 2.5 | |
| 146. |
What is the main drawback in NR method? |
| A. | Slow to converge |
| B. | A large memory allocation is required to store the jacobian matrix |
| C. | The number of iterations is more |
| D. | All of these |
| E. | None of these |
| Answer» C. The number of iterations is more | |
| 147. |
What is the main cause of voltage instability? |
| A. | Generators |
| B. | Transformers |
| C. | Loads |
| D. | Line losses |
| Answer» D. Line losses | |
| 148. |
What is the element of the graph that is not included in the tree called? |
| A. | Links |
| B. | Branches |
| C. | Oriented graph |
| D. | All of these |
| Answer» B. Branches | |
| 149. |
What is power angle equation of synchronous machines? |
| A. | An equation between electrical power generated to the angular displacement of the rotor |
| B. | An equation between mechanical power generated to the angular displacement of the rotor |
| C. | An equation between electrical power generated to the angular displacement of stator windings |
| D. | An equation between mechanical power generated to the angular displacement of stator windings |
| Answer» B. An equation between mechanical power generated to the angular displacement of the rotor | |
| 150. |
What is infinite bus in power system? |
| A. | A large system with infinite voltage |
| B. | A large system in which the voltage and frequency varies |
| C. | A large system whose voltage and frequency remains constant throughout. |
| D. | Both (a) and (b) |
| E. | None of these |
| Answer» D. Both (a) and (b) | |