1) What is the value of zero sequence impedance in line to line faults?
a. Z0 = 1
b. Z0 = ∞
c. Z0 = 3 Zn
d. Z0 = 0
|
2) What is the expression for fault current in line to line fault?
a. If = √3 * (Ea / Z1 + Z2)
b. If = 3 * (Ea / Z1 + Z2)
c. If = √3 * (Ea / Z1 + Z2 + Z0)
d. If = 3 * (Ea / Z1 + Z2 + Z0)
|
3) Which among these is the connection diagram for line to line faults?
a. Only a
b. Only b
c. Only c
d. Only d
e. None of these
|
4) What percentage of fault occurring in the power system is line to line fault?
a. 5 %
b. 30 %
c. 25 %
d. 15 %
|
5) What percentage of fault occurring in the power system is LLG fault?
a. 20 %
b. 30 %
c. 5 %
d. 10 %
|
6) What will be the value of current Ia, if the fault occurs between the lines B, C and ground?
a. Ia = 1
b. Ia = 0
c. Ia = ∞
d. Ia = - (Ib + Ic )
|
7) What is the value of fault current If, if the neutral grounding is absent in LLG fault?
a. If = - 3 Ia1 ( Z2 / Z2 + Z1)
b. If = 0
c. If = √3 * (Ea / Z1 + Z2 + Z0)
d. If = 3 * (Ea / Z1 + Z2 + Z0)
|
8) What is the expression for the current Ia2, if a double line to ground fault occurs on an unloaded generator through fault impedance?
a. Ia2 = - Ia1 * (Z0 + 3Zf) / ( Z0 + Z2 + 3Zf)
b. Ia2 = - Ia1 * (Z0 + 3Zf + Z2) / ( Z0 + Z2 + 3Zf)
c. Ia2 = - Ia0 * (Z0 + Zf) / ( Z0 + Z2 + 3Zf)
d. Ia2 = - Ia1 * Z2 * (Z0 + 3Zf) / ( Z0 + Z2 + 3Zf)
|
9) 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
|
10) 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
Explanation
Related Ques
|
ANSWER: The ability of the power system to regain the state of operating equilibrium point when the system is subjected to any disturbances.
Explanation:
No explanation is available for this question!
|
|
11) 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
|
12) 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
|
13) 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
Explanation
Related Ques
|
ANSWER: The maximum flow of power through a particular point in the power system without loss of stability when small disturbances occur.
Explanation:
No explanation is available for this question!
|
|
14) 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
|
15) 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
Explanation
Related Ques
|
ANSWER: The maximum flow of power through a particular point in the power system without loss of stability when large and sudden disturbances occur
Explanation:
No explanation is available for this question!
|
|
16) 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
|
17) 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
|
18) 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
|
19) 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
|
20) 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
|
21) 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
Explanation
Related Ques
|
ANSWER: To maintain steady voltages at all the buses after the occurrence of fault.
Explanation:
No explanation is available for this question!
|
|
22) What is the main cause of voltage instability?
a. Generators
b. Transformers
c. Loads
d. Line losses
|
23) 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
|
24) 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
Explanation
Related Ques
|
ANSWER: To maintain steady frequency following severe disturbances resulting in the imbalance between generators and load
Explanation:
No explanation is available for this question!
|
|
25) 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
|
26) 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
Explanation
Related Ques
|
ANSWER: The relative motion of the rotor with respect to stator field as a function of time.
Explanation:
No explanation is available for this question!
|
|
27) What is the size of the sub matrix “H “of the jacobian, if n1 is the number of PV buses and n2 the number of PQ buses?
a. (n1 + n2)2
b. n1 * n2
c. (n1 + n2) n1
d. (n1 + n2) n2
|
28) Initially what will be the voltage at all the PQ buses for solving the load flow problem using NR method?
a. Vi = 1 ∠ 90°
b. Vi = 1 ∠ 0°
c. Vi = 1 ∠ 180°
d. Vi = 1 ∠ 45°
|
29) 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
|
30) 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
|
31) 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
|
32) 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
|
33) 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
|
34) 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
|
35) What is the fault current expression in case of LLG faults?
a. If = 3 Ia1
b. If = 0
c. If = 3 Ia0
d. If = Ia1
|
