Explore topic-wise MCQs in Electrical Engineering Questions.

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.

51.

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
Discussion
52.

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
Discussion
53.

What does the swing equation describe?
A. The relative motion of rotor with the field windings of the machine
B. The relative motion of the rotor with respect to stator field as a function of time.
C. The relative motion of stator field with the rated frequency of the machine
D. The performance curve of the machine
Answer» C. The relative motion of stator field with the rated frequency of the machine
Discussion
54.

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
Discussion
55.

For what studies are the FDLF method used?
A. Optimisation studies
B. Multiple load flow studies
C. Small size systems
D. Both (a) and (b)
E. All of these
Answer» E. All of these
Discussion
56.

Which among the following methods is used for improving the system stability?
A. Increasing the system voltage
B. Reducing the transfer reactance
C. Using high speed circuit breaker
D. All of these
E. None of these
Answer» E. None of these
Discussion
57.

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
Discussion
58.

What percentage of fault occurring in the power system is line to line fault?
A. 5 %
B. 30 %
C. 25 %
D. 15 %
Answer» E.
Discussion
59.

The stability of the power system is not affected by which among these?
A. Generator reactance
B. Line losses
C. Excitation of generators
D. All of these
E. None of these
Answer» C. Excitation of generators
Discussion
60.

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
Discussion
61.

Which among these is a classification of power system stability?
A. Frequency stability
B. Voltage stability
C. Rotor angle stability
D. All of these
E. None of these
Answer» E. None of these
Discussion
62.

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
Discussion
63.

What is steady state stability limit?
A. The maximum flow of power through a particular point in the power system without loss of stability when small disturbances occur.
B. The maximum power flow possible through a particular component connected in the power system.
C. The maximum flow of power through a particular point in the power system without loss of stability when sudden disturbances occur
D. All of these
E. None of these
Answer» B. The maximum power flow possible through a particular component connected in the power system.
Discussion
64.

How are the zero sequence and negative sequence networks connected in case of LLG faults?
A. Parallel
B. Series
C. Can be connected in either way
D. Such type of connection does not exist
Answer» B. Series
Discussion
65.

What percentage of fault occurring in the power system is LLG fault?
A. 20 %
B. 30 %
C. 5 %
D. 10 %
Answer» E.
Discussion
66.

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
Discussion
67.

What is power system stability?
A. The maximum power flow possible through a particular component connected in the power system.
B. The ability of the power system to regain the state of operating equilibrium point when the system is subjected to any disturbances.
C. It is a phenomenon in which a power system losses its operating equilibrium when subjected to large disturbances.
D. All of these
E. None of these
Answer» C. It is a phenomenon in which a power system losses its operating equilibrium when subjected to large disturbances.
Discussion
68.

What is the value of transient stability limit?
A. Higher than steady state stability limit
B. Lower than steady state stability limit.
C. Depending upon the severity of load
D. All of these
E. None of these
Answer» C. Depending upon the severity of load
Discussion
69.

What is / are the major assumptions made in the calculation of swing equations?
A. Damper windings are neglected
B. The machine is lossless
C. The machine has to run at synchronous speed
D. Both (a) and (b)
E. All of these
Answer» E. All of these
Discussion
70.

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
Discussion
71.

For economic measure the generators at a power plant operate at _____________.
A. Equal incremental cost
B. Equal loads
C. Equal power rating
D. All of these
E. None of these
Answer» B. Equal loads
Discussion
72.

What is transient stability limit?
A. The maximum flow of power through a particular point in the power system without loss of stability when small disturbances occur.
B. The maximum power flow possible through a particular component connected in the power system.
C. The maximum flow of power through a particular point in the power system without loss of stability when large and sudden disturbances occur
D. All of these
E. None of these
Answer» D. All of these
Discussion
73.

By using which component can the transient stability limit of a power system be improved?
A. Series resistance
B. Series capacitor
C. Series inductor
D. Shunt resistance
Answer» C. Series inductor
Discussion
74.

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
Discussion
75.

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.
Discussion
76.

What is the main cause of voltage instability?
A. Generators
B. Transformers
C. Loads
D. Line losses
Answer» D. Line losses
Discussion
77.

What is / are the cause(s) for transient disturbance?
A. Sudden load changes
B. Faults in the power system
C. Switching operations
D. All of these
E. None of these
Answer» E. None of these
Discussion
78.

On what factors does the transient stability depend on?
A. Initial operating state
B. Severity of disturbances
C. Voltage instability
D. Both (a) and (b)
E. All of these
Answer» E. All of these
Discussion
79.

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.
Discussion
80.

What is frequency stability?
A. To maintain steady frequency following severe disturbance resulting in the imbalance between transformer and load
B. To maintain steady frequency following severe disturbances resulting in the imbalance between generators and load
C. To maintain a steady frequency in all the protection components and the transmission lines.
D. Both (a) and (b)
E. All of these
Answer» C. To maintain a steady frequency in all the protection components and the transmission lines.
Discussion
81.

What information does the swing curve provide?
A. Stability of the system.
B. Performance of the machine
C. The rotor performance
D. All of these
E. None of these
Answer» B. Performance of the machine
Discussion
82.

At what value of ‘δ’ the maximum power transfer takes place?
A. 45 °
B. 90 °
C. 120 °
D. 180 °
Answer» C. 120 °
Discussion
83.

What are the main applications of the swing curves?
A. Designing the rotor field windings
B. Designing the protective devices
C. Used to limit the size of the machine
D. All of these
E. None of these
Answer» C. Used to limit the size of the machine
Discussion
84.

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
Discussion
85.

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°
Discussion
86.

Why are the series capacitors used?
A. Improve the voltage
B. Reduce the fault level
C. Compensate for line inductive reactance and improve the stability of the power system.
D. Improves the power factor
Answer» D. Improves the power factor
Discussion
87.

How is the voltage and frequency controlled in automatic generation control?
A. By controlling the excitation
B. By controlling the turbine action
C. Turbine speed control for voltage and excitation control for frequency
D. Excitation control for voltage and turbine speed control for voltage.
Answer» D. Excitation control for voltage and turbine speed control for voltage.
Discussion
88.

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
Discussion
89.

What are the common assumptions made for the equal area criterion?
A. The transmission line and machine resistances are neglected.
B. Rotor speed of the machine is constant
C. Mechanical input remains constant.
D. All of these
E. None of these
Answer» E. None of these
Discussion
90.

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
Discussion
91.

With the use of high speed circuit breakers, which among the following stability is increased?
A. Steady state stability
B. Transient stability
C. Frequency stability
D. All of these
E. None of these
Answer» C. Frequency stability
Discussion
92.

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
Discussion
93.

For which among the following cases is the equal area criterion of stability used?
A. One machine and infinite bus bar
B. No load on bus bar
C. Many machines and infinite bus bar
D. All of these
E. None of these
Answer» B. No load on bus bar
Discussion
94.

Which stability information is obtained from the equal area criterion?
A. Absolute stability
B. Transient stability
C. Steady state stability
D. Both (b) and (c)
E. All of these
Answer» B. Transient stability
Discussion
95.

Which stability information is obtained from the equal area criterion?

A. Absolute stability
B. Transient stability
C. Steady state stability
D. Both (b) and (c)
E. All of these
Answer» B. Transient stability
Discussion
96.

Which types of equations are solved using Newton Raphson method?

A. Non linear differential equations
B. Linear differential equations
C. Non linear algebraic equations
D. Both (a) and (b)
E. All of these
Answer» D. Both (a) and (b)
Discussion
97.

Why are load flow studies carried out?

A. To study of stability of the system
B. For fault calculations
C. For planning the power system
D. All of these
Answer» D. All of these
Discussion
98.

Why are series reactors used?

A. Improve the transmission efficiency
B. Improve the power factor of the power system
C. To bring down the fault level with in the capacity of the switchgear instrument
D. All of these
Answer» D. All of these
Discussion
99.

Why are the series capacitors used?

A. Improve the voltage
B. Reduce the fault level
C. Compensate for line inductive reactance and improve the stability of the power system.
D. Improves the power factor
Answer» D. Improves the power factor
Discussion
100.

With the use of high speed circuit breakers, which among the following stability is increased?

A. Steady state stability
B. Transient stability
C. Frequency stability
D. All of these
E. None of these
Answer» C. Frequency stability
Discussion