1. An industrial consumer hall a daily load pattern of 2000 KW, 0.8 lag for 12 Hra and 1000 kW UPF for 12 Hr. The load factor is _____.
2. What is the maximum value of a load which consume 500 KWh per day at a load factor of 0.40, if the consumer increases the load factor of 0.50 without increasing the maximum demand?
3. A consumer consume. 600 kWh per day at a load factor of 0.40. If the consumer increases the load factor of 0.70 without increasing the maximum demand, what is the consumption of energy in kWh
4. The yearly load duration curve of a power plant is a straight line. The maximum load is 750 MW and the minimum load is 600 Mw. The capacity of the plant is 900 MW. What is the capacity factor and utilization factor?
5. What is the utilization factor of a power station which supplies the following loads?
6. A power station supplies the peak load of 60 Mw, 40 MW and 70 MW to three localities. The annual load factor is 0.50 p.u. and the diversity factor of the load at the station is 1.55. The maximum demand on the station and average load respectively will be
7. The load duration curve for a system, is shown in the figure below. The load factor will be
8. A generating station has a maximum demand of 50 Mw, a load factor of 60%, a plant capacity factor of 45% and if the plant while running as per schedule, were fully loaded. The daily energy produced will be
9. A generating st ation has a maximum, demand of 20 mW, load factor of 60%, a plant capacity factor of 50% and a plant Use factor of 72%. What is the reserve capacity of the plant, if the plant, while running as per schedule, were fully loaded?
10. In the above question, the maximum energy that could be produced daily is
11. In a DC transmission line ______.
12. The impedance of a circuit is given by z=3+j4. Its conductance will be
13. A 100 km transmission line ia deaigned for a nominal voltage of 132 kV and consists of one conductor per phase. The line reactance is 0.726 ohm/km. The static transmission capacity of the line, in Megawatts, would be
14. The per unit impedance of a 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
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
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
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
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
19. For equilateral spacing of conductors of an untrasposed 3-phase line, we have
20. For a 500 Hz frequency excitation, a 50 #em long power line will be modelled as
21. Which one of the following statement. is not correct for the use of bundled conductors in transmission lines?
22. The main consideration for higher and higher operating voltage of transmission is to
23. A single phase transmission line of impedance j 0.8 ohm supplies a resistive load of 500 A at 300 V. The sending end power factor is
24. A medium line with parameters A, B, C, D is extended by connecting a short line of impedance Z in series The overall ABCD parameters of the series combination will be
25. When bundle conductors are used in place of single conductors, the effective inductance and capacitance will respectively
26. To increase the visual critical voltage of cporona for an overhead line, one solid phase-conductor is replaced by a "bundle" of four smaller conductors per phase, having an aggregate cross-sectional area equal to that of the solid conductor. If the radius of the solid conductor is 40 mm, then the radius of each of the bundle conductors would be
27. For an existing ac transmision line, the string efficiency is 80%, if dc voltage is supplied for the same set up, the string efficiency will be
28. In a string of suspension insulators, the voltage distribution across the different units of a string could be made uniform by the use of a grading ring, because it
29. A three phase over head transmission line has its conductors horizontally spaced with spacing between adjacent conductors equal to 'd'. if now the conductors of the line are rearranged to form and equilateral triangle of sides equal to 'd' then
30. For a 500 Hz frequency excitation, a 50 km, long power line will be modeled as
31. If in a short transmission line, resistance and inductance are found to be equal and regulation appear. to be zero, then the load will
32. "Expanded ACSR" are conductors composed of
33. What is the sag for a span of 400m, if the ultimate tensile strength of conductor is 6000 kgf, and the weight of conductor is 550 kgf/km? Factor of safety is 2.
34. A transmission line has a span of 275 m between level supports. The conductor has a diameter of 19.58 mm, weight 0.844 kgpm and has an ultimate breaking strength of 7950 kgf. Each conductor has a radial covering of ice 9.58 mm thick and is subjected to a horizontal wind pressure of 40 k617m2 of ice covering projected area. If the factor of safety is 2, what is the deflected sag? Ice weight is 913.5 kg/m3
35. A transmission line conductor having a diameter of 19.5 mm, weight 850 kg/km. The span is 275 m. The wind pressure is 39 kg/m of projected area with ice coating of 13 mm. The ultimate strength of the conductor is'8000 kg. What is the maximum sag, if the factor of safety is 2 and ice weight 910 kg/m3?
36. A transmission line conductor at a river crossing is supported from two towers at height. of 30 m and 90m, above water level. The horizontal distance between the towers is 270m, if the tension in the conductor is 1800 kg and the conductor weight 1 kg/m. What is the clearance between the conductor and the water at a point midway between the towers?
37. An overhead transmission line has a span of 240m between level supports. What is the maximum sag if the conductor weight 727 kg/km and has a breaking strength of 6880 kg? Allow the factor of safety of 2. Neglecting wind and ice loading.
38. The line conductor of a transmission line has an overall diameter of 19.53 mm, weight 0.844 kg/m and an ultimate breaking strength of 7950 kg. If the factor of safety is to be 2, when conductor has an ice of 1 kg/m and a horizontal wind pressure of 1.5 kg/m. What is the vertical sag, corresponding to this loading for a 300 m span level supports?
39. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 20 mm and the spacing between conductors is 3m. What is the inductance of each conductor per km?
40. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 20mm and the spacing between conductor is 3m. When the conductor material is steel of relative permeability 50, the loop inductance per km of the line will be
41. A 1-pi line two conductors operate at 50Hz. The diameter of each conductor is 15 mm, and the spacing between the conductor is 3.5 m. The inductive reactance per km will be
42. A conductor is composed of seven identical copper strands, each having a radius r. The self GMD of the conductors will be _____.
43. The charging current per kill of the line is _____.
44. What is the time of operation of a relay of rating 5 amp 2.2 sec, IDMT and having a relay of setting of 125% Tms = 0.6 It is connected to a supply circuit through a CT, 400 ratio. The fault current is 400 amp.
45. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 2 cm and are spaced 3m apart. What is the line to line capacitance
46. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 4 cm and are spaced 6 m apart. What is the capacitive susceptance to neutral per km?
47. A three phase 50 Hz line consists of three conductors each of diameter 21 mm, The spacing between the conductors all follows: A - B = 3m, B - C = 5m, C - A = 3.6m If the line operates at 132 k V, the reactive volt ampere generated by the line per km is
48. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 20 mm and the spacing between the conductors is 3m, The height of conductor above the ground is 6 m. The capacitance of the line to neutral will be
49. For a 500 Hz frequency excitation, a 50 km long power line will be modeled as
50. Bundled conductors are employed to ______.
51. Series capacitive compensation in EHV transmission lines is used to
52. A lossless radial transmission line with surge impedance loading
53. The X:R ratio of 220 kV line as compared to 400 kV line is
54. If a line is 100 % series compensated it may result into series resonance at power frequency of
55. A 60 Hz, 320 km loss less line has Bending end voltage 1.0 p.u, The receiving end voltage on no load is
56. With 100 % series compensation of line.
57. For certain geometry and operating voltage of the uncompensated transmission line, the ratio of power transfer capability to the surge impedance loading with increase in length
58. The effect of series capacitance compensation is
59. For a long uncompensated line the limit to the line loading ill governed by
60. For any fixed degree of inductive shunt compensation, additional series capacitive compensation
61. With 100 % inductive shunt compensation, the voltage profile is flat for
62. A loss less line terminated with its surge impedance has
63. For reducing tower footing resistance it is better to Use
64. An RLC series. circuit remains predominantly inductive
65. The corona loss on a particular system at 50 Hz is 1 kw/phase per km. The corona loss on the same system with supply frequency 25 Hz will be
66. A voltage of 1000 kV is applied to an overhead line with its receiving end open. If the surge impedance of the line is 500 ohm, then the total surge power in the line is
67. The main criterion for selection of the size of a distribution for a radial distribution system is
68. If an induction machine is run at above synchronous speed, it acts as
69. The low voltage winding of a 400/230 V, 1-phase, 50 Hz transformer is to be connected to a 25 Hz, the supply voltage should be
70. Corona losses are minimized when ______.
71. The order of the sub-harmonic during SSR for 50 Hz normal frequency is ____.
72. The non-uniform distribution of voltage across the units in a string of suspension type insulators is due to
73. Whenever the conductors are dead-ended of there is a change in the direction of transmission line, the insulator. used are of the
74. The time taken for a surge to travel a 600 km long overhead transmission line is
75. The function of the earth wire in an extra high voltage line is to
76. A long overhead transmission line is terminated by its characteristic impedance. Under this operating condition, the ratio of the voltage to the current at different points along the line will
77. For a transmission line with negligible losses, the lagging reactive power (VAR) delivered at the receiving end, for a given receiving end voltage, is directly proportional to the
78. Corona loss can be reduced by the use of hollow conductors because
79. The insulation of modern EHV lines is designed based on
80. Shunt compensation in an EHV line is used _____.
81. In a 3-core extra-high voltage cable, a metallic screen around each core insulation is provided to _____.
82. The single phase line of 280 V and 3 pha.e line of 400 V which feed different domestic circuit. and induetrial loade represent
83. The transmission line feeding power on either side of the main transmission line is called
84. Series capacitive compensation on EHV transmission lines is used to
85. At a particular unbalanced node, the real powers specified are Leaving the node : 20 Mw, 25 Mw, Entering the node: 60 Mw, 30 MW. The balance power will be
86. When a d.c source is switched is purely inductive, the current response is
87. If transformer frequency is changed from 60 Hz, to 60 Hz the ratio of eddy current loss 60 Hz to 50 Hz, at constant voltage will be
88. In load flow analysis, the load connected at a bus is represented as _____.
89. If the reference bus is changed in two load flow runs with same system data and power obtained for reference bur taken a. specified P and Q in the latter run
90. A square matrix is called singular if its
91. Gauss-Seidel iterative method can be used for solving a set of
92. Pure inductive circuit takes power (reactive) from the a.c. line when
93. An alternator has a phase sequence of RYB for its phase voltage. In case of field current is reversed, the phase sequence will become
94. An alternator has a phase sequence of RYB for its phase voltage. In case the direction of rotation of alternator is reversed, the phase sequence will become
95. A synchronous generator connected to an infinite bus delivers power at a lag p.r. If its excitation is increased
96. A synchronous motor connected to an infinite bUB takes power at a lag p.f. If its excitation is increased
97. In case of 3 phase short circuit in a system the power fed into the system is
98. With the help of a reactive compensator it is possible to have
99. For a long uncompensated line the limit to the line loading is governed by
100. A shunt reactor at 100 MVA is operated at 98% of its rated voltage and at 96% of its rated frequency. The reactive power absorbed by the reactor is
2. What is the maximum value of a load which consume 500 KWh per day at a load factor of 0.40, if the consumer increases the load factor of 0.50 without increasing the maximum demand?
3. A consumer consume. 600 kWh per day at a load factor of 0.40. If the consumer increases the load factor of 0.70 without increasing the maximum demand, what is the consumption of energy in kWh
4. The yearly load duration curve of a power plant is a straight line. The maximum load is 750 MW and the minimum load is 600 Mw. The capacity of the plant is 900 MW. What is the capacity factor and utilization factor?
5. What is the utilization factor of a power station which supplies the following loads?
6. A power station supplies the peak load of 60 Mw, 40 MW and 70 MW to three localities. The annual load factor is 0.50 p.u. and the diversity factor of the load at the station is 1.55. The maximum demand on the station and average load respectively will be
7. The load duration curve for a system, is shown in the figure below. The load factor will be
8. A generating station has a maximum demand of 50 Mw, a load factor of 60%, a plant capacity factor of 45% and if the plant while running as per schedule, were fully loaded. The daily energy produced will be
9. A generating st ation has a maximum, demand of 20 mW, load factor of 60%, a plant capacity factor of 50% and a plant Use factor of 72%. What is the reserve capacity of the plant, if the plant, while running as per schedule, were fully loaded?
10. In the above question, the maximum energy that could be produced daily is
11. In a DC transmission line ______.
12. The impedance of a circuit is given by z=3+j4. Its conductance will be
13. A 100 km transmission line ia deaigned for a nominal voltage of 132 kV and consists of one conductor per phase. The line reactance is 0.726 ohm/km. The static transmission capacity of the line, in Megawatts, would be
14. The per unit impedance of a 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
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
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
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
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
19. For equilateral spacing of conductors of an untrasposed 3-phase line, we have
20. For a 500 Hz frequency excitation, a 50 #em long power line will be modelled as
21. Which one of the following statement. is not correct for the use of bundled conductors in transmission lines?
22. The main consideration for higher and higher operating voltage of transmission is to
23. A single phase transmission line of impedance j 0.8 ohm supplies a resistive load of 500 A at 300 V. The sending end power factor is
24. A medium line with parameters A, B, C, D is extended by connecting a short line of impedance Z in series The overall ABCD parameters of the series combination will be
25. When bundle conductors are used in place of single conductors, the effective inductance and capacitance will respectively
26. To increase the visual critical voltage of cporona for an overhead line, one solid phase-conductor is replaced by a "bundle" of four smaller conductors per phase, having an aggregate cross-sectional area equal to that of the solid conductor. If the radius of the solid conductor is 40 mm, then the radius of each of the bundle conductors would be
27. For an existing ac transmision line, the string efficiency is 80%, if dc voltage is supplied for the same set up, the string efficiency will be
28. In a string of suspension insulators, the voltage distribution across the different units of a string could be made uniform by the use of a grading ring, because it
29. A three phase over head transmission line has its conductors horizontally spaced with spacing between adjacent conductors equal to 'd'. if now the conductors of the line are rearranged to form and equilateral triangle of sides equal to 'd' then
30. For a 500 Hz frequency excitation, a 50 km, long power line will be modeled as
31. If in a short transmission line, resistance and inductance are found to be equal and regulation appear. to be zero, then the load will
32. "Expanded ACSR" are conductors composed of
33. What is the sag for a span of 400m, if the ultimate tensile strength of conductor is 6000 kgf, and the weight of conductor is 550 kgf/km? Factor of safety is 2.
34. A transmission line has a span of 275 m between level supports. The conductor has a diameter of 19.58 mm, weight 0.844 kgpm and has an ultimate breaking strength of 7950 kgf. Each conductor has a radial covering of ice 9.58 mm thick and is subjected to a horizontal wind pressure of 40 k617m2 of ice covering projected area. If the factor of safety is 2, what is the deflected sag? Ice weight is 913.5 kg/m3
35. A transmission line conductor having a diameter of 19.5 mm, weight 850 kg/km. The span is 275 m. The wind pressure is 39 kg/m of projected area with ice coating of 13 mm. The ultimate strength of the conductor is'8000 kg. What is the maximum sag, if the factor of safety is 2 and ice weight 910 kg/m3?
36. A transmission line conductor at a river crossing is supported from two towers at height. of 30 m and 90m, above water level. The horizontal distance between the towers is 270m, if the tension in the conductor is 1800 kg and the conductor weight 1 kg/m. What is the clearance between the conductor and the water at a point midway between the towers?
37. An overhead transmission line has a span of 240m between level supports. What is the maximum sag if the conductor weight 727 kg/km and has a breaking strength of 6880 kg? Allow the factor of safety of 2. Neglecting wind and ice loading.
38. The line conductor of a transmission line has an overall diameter of 19.53 mm, weight 0.844 kg/m and an ultimate breaking strength of 7950 kg. If the factor of safety is to be 2, when conductor has an ice of 1 kg/m and a horizontal wind pressure of 1.5 kg/m. What is the vertical sag, corresponding to this loading for a 300 m span level supports?
39. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 20 mm and the spacing between conductors is 3m. What is the inductance of each conductor per km?
40. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 20mm and the spacing between conductor is 3m. When the conductor material is steel of relative permeability 50, the loop inductance per km of the line will be
41. A 1-pi line two conductors operate at 50Hz. The diameter of each conductor is 15 mm, and the spacing between the conductor is 3.5 m. The inductive reactance per km will be
42. A conductor is composed of seven identical copper strands, each having a radius r. The self GMD of the conductors will be _____.
43. The charging current per kill of the line is _____.
44. What is the time of operation of a relay of rating 5 amp 2.2 sec, IDMT and having a relay of setting of 125% Tms = 0.6 It is connected to a supply circuit through a CT, 400 ratio. The fault current is 400 amp.
45. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 2 cm and are spaced 3m apart. What is the line to line capacitance
46. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 4 cm and are spaced 6 m apart. What is the capacitive susceptance to neutral per km?
47. A three phase 50 Hz line consists of three conductors each of diameter 21 mm, The spacing between the conductors all follows: A - B = 3m, B - C = 5m, C - A = 3.6m If the line operates at 132 k V, the reactive volt ampere generated by the line per km is
48. A two conductor 1 - pi line operates at 50 Hz. The diameter of each conductor is 20 mm and the spacing between the conductors is 3m, The height of conductor above the ground is 6 m. The capacitance of the line to neutral will be
49. For a 500 Hz frequency excitation, a 50 km long power line will be modeled as
50. Bundled conductors are employed to ______.
51. Series capacitive compensation in EHV transmission lines is used to
52. A lossless radial transmission line with surge impedance loading
53. The X:R ratio of 220 kV line as compared to 400 kV line is
54. If a line is 100 % series compensated it may result into series resonance at power frequency of
55. A 60 Hz, 320 km loss less line has Bending end voltage 1.0 p.u, The receiving end voltage on no load is
56. With 100 % series compensation of line.
57. For certain geometry and operating voltage of the uncompensated transmission line, the ratio of power transfer capability to the surge impedance loading with increase in length
58. The effect of series capacitance compensation is
59. For a long uncompensated line the limit to the line loading ill governed by
60. For any fixed degree of inductive shunt compensation, additional series capacitive compensation
61. With 100 % inductive shunt compensation, the voltage profile is flat for
62. A loss less line terminated with its surge impedance has
63. For reducing tower footing resistance it is better to Use
64. An RLC series. circuit remains predominantly inductive
65. The corona loss on a particular system at 50 Hz is 1 kw/phase per km. The corona loss on the same system with supply frequency 25 Hz will be
66. A voltage of 1000 kV is applied to an overhead line with its receiving end open. If the surge impedance of the line is 500 ohm, then the total surge power in the line is
67. The main criterion for selection of the size of a distribution for a radial distribution system is
68. If an induction machine is run at above synchronous speed, it acts as
69. The low voltage winding of a 400/230 V, 1-phase, 50 Hz transformer is to be connected to a 25 Hz, the supply voltage should be
70. Corona losses are minimized when ______.
71. The order of the sub-harmonic during SSR for 50 Hz normal frequency is ____.
72. The non-uniform distribution of voltage across the units in a string of suspension type insulators is due to
73. Whenever the conductors are dead-ended of there is a change in the direction of transmission line, the insulator. used are of the
74. The time taken for a surge to travel a 600 km long overhead transmission line is
75. The function of the earth wire in an extra high voltage line is to
76. A long overhead transmission line is terminated by its characteristic impedance. Under this operating condition, the ratio of the voltage to the current at different points along the line will
77. For a transmission line with negligible losses, the lagging reactive power (VAR) delivered at the receiving end, for a given receiving end voltage, is directly proportional to the
78. Corona loss can be reduced by the use of hollow conductors because
79. The insulation of modern EHV lines is designed based on
80. Shunt compensation in an EHV line is used _____.
81. In a 3-core extra-high voltage cable, a metallic screen around each core insulation is provided to _____.
82. The single phase line of 280 V and 3 pha.e line of 400 V which feed different domestic circuit. and induetrial loade represent
83. The transmission line feeding power on either side of the main transmission line is called
84. Series capacitive compensation on EHV transmission lines is used to
85. At a particular unbalanced node, the real powers specified are Leaving the node : 20 Mw, 25 Mw, Entering the node: 60 Mw, 30 MW. The balance power will be
86. When a d.c source is switched is purely inductive, the current response is
87. If transformer frequency is changed from 60 Hz, to 60 Hz the ratio of eddy current loss 60 Hz to 50 Hz, at constant voltage will be
88. In load flow analysis, the load connected at a bus is represented as _____.
89. If the reference bus is changed in two load flow runs with same system data and power obtained for reference bur taken a. specified P and Q in the latter run
90. A square matrix is called singular if its
91. Gauss-Seidel iterative method can be used for solving a set of
92. Pure inductive circuit takes power (reactive) from the a.c. line when
93. An alternator has a phase sequence of RYB for its phase voltage. In case of field current is reversed, the phase sequence will become
94. An alternator has a phase sequence of RYB for its phase voltage. In case the direction of rotation of alternator is reversed, the phase sequence will become
95. A synchronous generator connected to an infinite bus delivers power at a lag p.r. If its excitation is increased
96. A synchronous motor connected to an infinite bUB takes power at a lag p.f. If its excitation is increased
97. In case of 3 phase short circuit in a system the power fed into the system is
98. With the help of a reactive compensator it is possible to have
99. For a long uncompensated line the limit to the line loading is governed by
100. A shunt reactor at 100 MVA is operated at 98% of its rated voltage and at 96% of its rated frequency. The reactive power absorbed by the reactor is
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