# Power System Operations and Control 3

Electrical Engineering MCQ Question Papers: Campus Placement

Subject: Power System Operations and Control 3

Part 3: List for questions and answers of Power System Operations and Control

Q1. To control which among the following is the regulating transformer used in a power system?

a) Power flows

b) Frequency

c) Voltage

d) Power factor

Q2. 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

Q3. 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

Q4. 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

Q5. Which among theses quantities are to be determined in slack bus?

a) P and Q

b) Q and |V|

c) |V| and d

d) Q and d

Q6. What happens to the value of the fault current in case of SLG fault, if fault impedance is introduced?

a) The fault current increase

b) The fault current remains same as in case of SLG fault

c) The fault current becomes zero

d) The fault current is reduced

Q7. What happens if the neutral is not grounded in case of the single line to ground fault?

a) Only the zero sequence impedance will be zero

b) The zero sequence impedance will be infinite

c) Fault current will be zero

d) Both (b) and (c)

Q8. What are cross country faults?

a) A fault occurring at any point of the power system

b) Two or more faults occurring simultaneously on the power system

c) Line to line fault

d) All of these

Q9. What percentage of faults occurring is single line to ground fault?

a) 50 %

b) 60 %

c) 35 %

d) 70 %

Q10. What are the types of unsymmetrical faults?

a) Single line to ground fault

b) Double line to ground fault

c) Line to line fault

d) All of these

Q11. Zero sequence currents cannot flow in which of the following connections?

a) Delta

b) Star

c) Star – star

d) Both (b) and (c)

Q12. Phase shift of symmetrical components happens in which among the following?

a) Delta – delta

b) Star – delta

c) Delta – star

d) Both (b) and (c)

Q13. The positive sequence current is always equal to ________

a) Always zero

b) 1/3 of the negative sequence current

c) Negative sequence current

d) 3 times the negative sequence current

Q14. What is the value of (1+ a + a^2)?

a) 0

b) 1

c) -1

d) 8

Q15. In what direction does the phasor get rotated if it is multiplied by the operator ‘a’?

a) Anti clockwise

b) Clockwise

c) Gets rotated by 90° in the clockwise direction

d) Gets rotated by 90° in the anticlockwise direction

Q16. A balanced three phase system consists of ______

a) Zero sequence currents only

b) Positive sequence currents only

c) Positive, negative and zero sequence currents

d) Only negative sequence currents

Q17. Which among the following quantities are to be determined in voltage controlled bus?

a) P and Q

b) Q and |V|

c) |V| and d

d) Q and d

Q18. What percentage of buses in the power system are generator buses?

a) 5 %

b) 25 %

c) 70 %

d) 10 %

Q19. 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 d

Q20. 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 d

Part 3: List for questions and answers of Power System Operations and Control