11. In a DC transmission line
(a) it is necessary for the sending end and receiving end to be operated in synchronism.
(b) the effects of inductive and capacitive reactances are greater than in an AC transmission line of the same rating.
(c) there are no effects due to inductive and capacitive reactances.
(d) power transfer capability is limited by stability considerations.
Ans: c
12. The impedance of a circuit is given by z=3+j4. Its conductance will be
(a) 1/3
(b) 3/5
(c) 3/25
(d) 4/5
Ans: c
13. A 100 km transmiesion line ia deaigned for a nominal voltage of 132 kV and conaiala of one conductor per phase. The line reactance is 0.726 ohm/km. The static transmission capacity of the line, in Megawatts, would be
(a) 132
(b) 240
(c) 416
(d) 720
Ans: c
14. The per unit impedance ofa circuit element is 0.15. If the base kV and base MVA are halved, then the new value of the per unit impedance of the circuit element will be
(a) 0.075
(b) 0.15
(c) 0.30
(d) 0.600
Ans: c
15. The conductor of a 10 km long, single phase, two wire line are separated by a distance of 1.5 m. The diameter of each conductor is 1 cm, If the conductors are of copper, the inductance of the circuit is
(a) 50.0 mH
(b) 45.3 mH
(c) 23.8 mH
(d) 19.6 mH
Ans: c
16. For a single phase overhead line having solid copper conductors of diameter 1 cm, spaced 60 cm between centers, the inductance in mH/km is
(a) 0.05 + 0.2 ln 60
(b) 0.2 ln 60
(c) 0.05 + 0.2 ln (6010.5)
(d) 0.2 ln (60/0.5)
Ans: c
17. A 100 km long transmission line is loaded at 110 kV.if the loss of line is 5 MW and the load is 150 MVA, the resistance of the line is
(a) 8.06 ohms per phase
(b) 0.806 ohms per phase
(c) 0.0806 ohms per phase
(d) 80.6 ohms per phase
Ans: a
18. A 3-phase, 11 kv, 50 Hz, 200 kW load has a power factor of 0.8 lag. A delta connected 3-phase capacitor is used to improve the power factor to unity. The capacitance perphase of the capacitor in micro-farads is
(a) 3.948
(b) 1.316
(c) 0.439
(d) 11.844
Ans: b
19. For equilateral spacing of conductors of an untrasposed 3-phase line, we have
(a) balanced receiving end voltage and no communication interference
(b) unbalanced receiving end voltage and no communication interference
(c) balanced receiving end voltage and communication interference
(d) unbalanced receiving end voltage and communication interference.
Ans: c
20. For a 500 Hz frequency excitation, a 50 #em long power line will be modelled as
(a) short line
(b) medium line
(c) long line
(d) data insufficient for decision
Ans: c
Read More Questions:
Power Systems MCQs Part1
Power Systems MCQs Part2
(a) it is necessary for the sending end and receiving end to be operated in synchronism.
(b) the effects of inductive and capacitive reactances are greater than in an AC transmission line of the same rating.
(c) there are no effects due to inductive and capacitive reactances.
(d) power transfer capability is limited by stability considerations.
Ans: c
12. The impedance of a circuit is given by z=3+j4. Its conductance will be
(a) 1/3
(b) 3/5
(c) 3/25
(d) 4/5
Ans: c
13. A 100 km transmiesion line ia deaigned for a nominal voltage of 132 kV and conaiala of one conductor per phase. The line reactance is 0.726 ohm/km. The static transmission capacity of the line, in Megawatts, would be
(a) 132
(b) 240
(c) 416
(d) 720
Ans: c
14. The per unit impedance ofa circuit element is 0.15. If the base kV and base MVA are halved, then the new value of the per unit impedance of the circuit element will be
(a) 0.075
(b) 0.15
(c) 0.30
(d) 0.600
Ans: c
15. The conductor of a 10 km long, single phase, two wire line are separated by a distance of 1.5 m. The diameter of each conductor is 1 cm, If the conductors are of copper, the inductance of the circuit is
(a) 50.0 mH
(b) 45.3 mH
(c) 23.8 mH
(d) 19.6 mH
Ans: c
16. For a single phase overhead line having solid copper conductors of diameter 1 cm, spaced 60 cm between centers, the inductance in mH/km is
(a) 0.05 + 0.2 ln 60
(b) 0.2 ln 60
(c) 0.05 + 0.2 ln (6010.5)
(d) 0.2 ln (60/0.5)
Ans: c
17. A 100 km long transmission line is loaded at 110 kV.if the loss of line is 5 MW and the load is 150 MVA, the resistance of the line is
(a) 8.06 ohms per phase
(b) 0.806 ohms per phase
(c) 0.0806 ohms per phase
(d) 80.6 ohms per phase
Ans: a
18. A 3-phase, 11 kv, 50 Hz, 200 kW load has a power factor of 0.8 lag. A delta connected 3-phase capacitor is used to improve the power factor to unity. The capacitance perphase of the capacitor in micro-farads is
(a) 3.948
(b) 1.316
(c) 0.439
(d) 11.844
Ans: b
19. For equilateral spacing of conductors of an untrasposed 3-phase line, we have
(a) balanced receiving end voltage and no communication interference
(b) unbalanced receiving end voltage and no communication interference
(c) balanced receiving end voltage and communication interference
(d) unbalanced receiving end voltage and communication interference.
Ans: c
20. For a 500 Hz frequency excitation, a 50 #em long power line will be modelled as
(a) short line
(b) medium line
(c) long line
(d) data insufficient for decision
Ans: c
Read More Questions:
Power Systems MCQs Part1
Power Systems MCQs Part2
No comments:
Post a Comment