Power System Operation and Control (2180909) MCQs

MCQs of Reactive Power and Voltage Control

Showing 11 to 20 out of 40 Questions
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11.
A three phase, 50 Hz transmission line operates at 220 kV. The line has 400 Ω surge impedance. If the voltage grade of line is upgraded to 400 kV then how much surge impedance loading (SIL) is increased with respect to the SIL at 200 kV
(a) 279 MVA
(b) 200 MVA
(c) 300 MVA
(d) 400 MVA
Answer:

Option (a)

12.
A cable has surge impedance of 50 Ω and operates at 500 kV (L-L) at 50 Hz. If the electrical line length is 30 ° equivalent, find the steady state stability limit
(a) 5000 MW
(b) 10000 MW
(c) 15000 MW
(d) 18000 MW
Answer:

Option (b)

13.
A cable has surge impedance of 50 Ω and operates at 500 kV(L-L) at 50 Hz. If the electrical line length is 30 ° equivalent, obtain the value of transmission angle and the reactive power requirements at both ends of cable when the transmitted power through the cable is 50% of the SIL value
(a) 15.47 °, -1115.87 MVAR
(b) 11.35 °, -1115.87 MVAR
(c) 14.47 °, -1171.87 MVAR
(d) 20.47 °, -2115.87 MVAR
Answer:

Option (c)

14.
A cable has surge impedance of 50 Ω and operates at 500 kV(L-L) at 50 Hz. If the electrical line length is 30 ° equivalent, obtain the reactive power requirements at both ends of cable when the transmitted power through the cable is 125% of the SIL value
(a) 703.12 MVAR
(b) 1000.11 MVAR
(c) 1500.34 MVAR
(d) 2050.33 MVAR
Answer:

Option (a)

15.
A long line interconnects two grids. The surge impedance of line is 400 Ωand the line length is equivalent to 16 ° electrical. If the line voltage is 400 kV and power transfer through the line be 200 MW, find the power angle at the mid point of line
(a) 5 °
(b) 4 °
(c) 8 °
(d) 10 °
Answer:

Option (b)

16.
A long line interconnects two grids. The surge impedance of line is 400 Ωand the line length is equivalent to 16 ° electrical.The line voltage is 400 kV and power transfer through the line be 200 MW. What is the mid point voltage?
(a) 410 kV
(b) 400 kV
(c) 403 kV
(d) 402 kV
Answer:

Option (c)

17.
Voltage collapse typically occurs in the power system due to
(a) Heavily loaded line
(b) Faulted line
(c) Reactive power shortages in line
(d) All of above
Answer:

Option (d)

18.
Power system stability means
(a) Power system remains in a state of equilibrium under normal operating condition
(b) To restore an acceptable state of equilibrium after a disturbance
(c) Both a and b
(d) None of above
Answer:

Option (c)

19.
Which of the following is the short term stability in a generator driven system?
(a) Rotor-angle stability
(b) Short term voltage stability
(c) Frequency Stability
(d) Long-term voltage stability
Answer:

Option (a)

20.
Which of the following is the long term stability in a generator driven system?
(a) Rotor-angle stability
(b) Short term voltage stability
(c) Frequency Stability
(d) Long-term voltage stability
Answer:

Option (c)

Showing 11 to 20 out of 40 Questions
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