Objective Type Questions for -Power System Operation and Control Final Year

MEWAR UNIVERSITY OPERATION AND CONTROL DEPARTMENT OF ELECTRICAL ENGINEERING SEMESTER

POWER SYSTEM B. TECH. 4 Th YEAR 8Th

MEWAR UNIVERSITY DEPARTMENT OF ELECTRICAL ENGINEERING POWER SYSTEM OPERATION AND CONTROL B. TECH. 4Th YEAR 8Th SEMESTER

UNIT – 1 Questions 1 to 4 refer to the figures given below:

The input-output curves for two units with supply in parallel a common load are shown in the figure Q 1. When a load of 10 MW is equally shared by the two generators, the combined input must be (A) 250 x 105 kcal / hr (B) 350 x 105 kcal / hr (C) 500 x 105 kcal / hr (D) 600 x 105 kcal / hr



Q 2. If the two generators have individual ratings of 10 MW each, a system load of 16 MW should be shared as (A) 8 MW on each generator (B) 10 MW on A and 6 MW on B (C) 10 MW on B and 6 MW on A (D) 9 M W on A and 7 MW on B Q 3. Load shedding is done (A) To reduce heat demand (B) To improve power factor (C) To run the equipment efficiency (D) To repair the machine Q 4. If both generators have 2 MW load each then which of the following statements is correct? (A) Generator A runs at higher speed as compared to generator B (B) Generator B runs more efficiently as compared to generator A (C) Input to generator A is less than 75% of the input to generator B (D) Input to generator B is less than the input to generator A by about 23% Questions 5 and 6 refer to the data given below: A bulk supply was taken by a large industrial consumer at the rate of Rs 80 per KW plus 2 5 paisa per KWh

Q 5.

Q 6.

The average charge per KWh when the load factor is 20% (A) 3 cents (B) 5 cents (C) 7 cents (D) cannot be determined on the basis of the information provided

will be

The average charges per KWh will be least when the plant load factor is (A) 100% (B) 75% (C) 50% (D) 20%


Q 7.


Which statement about the daily load curve is valid? (A) The area under the curve gives the average demand (B) The ratio of the area under the curves to the total area of rectangle in which it is contained gives the load factor for the day (C) The peak of the curve gives the 'installed capacity of the plant (D) The area of the curves divided by the number of hours gives load factor

Q 8. An Equipment purchased for Rs10, 000 two years ago has a market value of Rs 12500 at present. It can be concluded that (A) the value has depreciated according to straight line method (B) the value has depreciated according to diminishing value method (C) the value has depreciated according to sinking fund method (D) the value has appreciated with the time Q 9.

In a steam power plant which component needs maximum maintenance attention? (A) Condenser (B) Boiler (C) Turbine (D) Water treatment plant

Questions 10 to 14 refer to the following data:



Four loads as shown in figure given below are connected to a power station Abscise is time from 0 to 24 hrs in all cases, Ordinate represents the load in KW Q 10.

Which load has the lowest average demand? Load A Load B Load C Load D

Q 11.

Which loads offer the identical average load? (A) A and B (B) B and C (C) C and D (D) A, B and D

Q 12.

The peak load on the plant is



(A) 3000 KW (B) 3500 KW (C) 4000 KW (D) 4250 KW Q 13.

The load factor of the plant supplying power to these loads will be nearly (A) 11% (B) 15% (C) 18% (D) 21%

Q 14.

The diversity factor of the plant supplying these loads will be (A) 0.5 (B) 1.0 (C) 1.5 (D) 0.2

Define the equations Q 15. n

∑ PGi−P D −P Loss=0 i=1

(A) Real Power balance constraints (B) Generation capacity constraint (C) Both A and B (D) None of them

Q 16.

max Pmin Gi ≤ P Gi ≤ P Gi , i=1,2, … … . , N


(A) Real Power balance constraints (B) Generation capacity constraint (C) Both A and B (D) None of them

Q 17.

Sli ≤ Smaxli, i = 1, ..., NL (A) Real Power balance constraints (B) Generation capacity constraint (C) Security constraints (D) None of them

N

Q 18.

F ( PGi )=∑ ai +bi PGi + c i P2Gi W h ere i=1, … … … … , N i=0

(A) Real Power balance constraints (B) Generation capacity constraint (C) Security constraints (D) None of them

Q 19.

Following power plant has instant starting (A) nuclear power plant (B) hydro power plant (C) diesel power plant (D) both (b) and (c)



Q 20.

(B) Hydro (C) Thermal (D) Diesel This curve is showing?

(A) Increment Fuel Cost Curve (B) Input Output Curve (C) Operating cost curve (D) None of these Q 22.

Optimal system operation involved (A) Economy of operation (B) System security (C) Emissions at certain fossil- fuel plants (D) All of above

Q 23.

B. TECH. 4 Th YEAR 8Th

Which of the following generating station has minimum ruining cost? (A) Nuclear

Q 21.

POWER SYSTEM

Optimal system operation may say as (A) Economy of operation of Power System (B) Emission of operation of Power System


(C) Both A and B (D) None of them

Q 24.

The economic dispatch problem is use to calculate (A) Minimize the total cost of generating real power (B) Minimize the total cost of generating reactive power (C) Both A and B (D) None of them

Q 25.

Optimal system operation involved (A) Economy of operation (B) System security (C) Both A and B (D) None of them

Q 26.

Which power plant is neglecting operating cost (A) Hydro plant (B) Thermal plants (C) Nuclear plant (D) None of them

Q 27.

Which power plant is considering operating cost (A) Hydro plant (B) Thermal plants (C) Nuclear plant (D) Both B and C



Q 28.

Input-output curve of a generating unit draw in between (A) Operating cost and power generation (B) Power Generation And Operating Cost (C) Both Of Above (D) None Of These

Q 29.

Operating cost consist of (A) Fuel cost (B) Maintenance cost (C) Both A and B (D) Only A

Q 30.

Incremental cost curve is (A) Slope of Input output curve (B) Slope of load curve (C) Both A and B (D) None of above

Q 31.

A generating station is not economical at (A) Above the PGi min (B) Equal to the PGi (C) Below the PGi max (D) Below the PGi min

Q 32.

A generating station is not economical at (A) Equal to the PGi min (B) Equal to the PGi (C) Above the PGi max (D) Above the PGi min

Q 33.

A generating station is economical at (A) Equal to the PGi min (B) Equal to the PGi (C) Below the PGi max




(D) All the above Q 34.

Incremental fuel cost( IC) define as d Ci d PGi d PGi (B) IC= d Ci (A) IC=

N

2 (C) IC=∑ a i+ bi PGi +c i PGi i=0

(D) None of these Q 35.

The system constraint are (A) Equality Constraint (B) Inequality constraint (C) Both A and B (D) None of these

Q 36.

Increment the IC value by ΔIC in case of n

(A)

∑ PGi−P D <0 i=1 n

(B)

∑ PGi−P D >0 i=1 n

(C)

∑ PGi−P D =0 i=1


Increment the IC value by ΔIC in case of n

(A)

∑ PGi−P D <0 i=1 n

(B)

∑ PGi−P D >0 i=1 n

(C)

∑ PGi−P D =0 i=1

(D) None of these Q 38. “Its loading from now on is held fixed at this value and the balance load is then shared between the remaining generators on equal incremental cost basis.” This theory knows



(A) Patton’s security theory (B) Kuhn-Tucker theory (C) Both A and B (D) None of these

Q 39.

Incremental fuel costs in rupees per MWh for a plant consisting of two units are:

IC 1=0.20 PG 1+ 40 IC 2=0.25 PG 2 +30 Where PG 1 and PG 2 (in MW) are power generated by both the units for a total demand of 250 MW, The total shared by the two units are (A) PG 1=

350 400 ∧PG2= 3 3

(B) PG 1=100∧PG 2=250 (C) PG 1=125∧PG 2=125 (D) PG 1=150∧PG 2=100

Q 40. “Its loading from now on is held fixed at this value and the balance load is then shared between the remaining generators on equal incremental cost basis.” This theory knows (A) Patton’s security theory (B) Kuhn-Tucker theory (C) Both A and B (D) None of these Q 41.

Dynamic programming method equation is (A) (B) (C) (D)

min

F N (x )= Y {F N ( y ) + F N −1 ( x− y ) } min F N (x )= Y {F N ( y ) + F N −1 ( x+ y ) } min F N (x )= Y {F N −1 ( y ) + F N ( x− y ) } min F N (x )= Y {F N ( y ) + F N +1 ( x− y ) }

Questions 42 to 44 refer to the data given below:



The input-output curve of a 0.5 MW generating stations is defined by I = 30 + 0.8 L + 0.5 L2 Where I is in MKcal and L is in megawatts Q 42.

The input when the plant was running on no load was (A) 0.5 kcal (B) 31.3 kcal (C) 30 x 106 kcal (D) zero

Q 43.

Total input when the plant was generating 35 MW was (A) 181 x 106 kcal/hr (B) 250 x 106 kcal/hr (C) 362.5 x 106 kcal/hr (D) 582xl26 kcal/hr

Q 44. When the load on the generator was 25 MW the heat rate in kcal / MW hr was nearly (A) 16 x 106 (B) 20 x 106 (C) 30 x 106 (D) 31.3 x 106 Questions 45 to 48 refer to the data given below: Manufacturer A offers his equipment costing Rs 150,000 + 45 x KW guaranteed to give the following operating cost Rs 18 + 0.007 KWh

the equipment is

Manufacturer B offers his equipment costing Rs 1, 12000 + 50 x KW The operating cost is guaranteed as Rs 16.50 + 0.0072 KWh



KW indicates machine rating and KWh indicates output Q 45.

Which machine is cheaper to own in 5000 KW range (A) Machine supplied by manufacturer A (B) Machine supplied by manufacturer B (C) Both have identical initial cost (D) Both have identical operating cost

Q 46.

At what KW rating the initial cost of the two machines will be identical? (A) 5500 KW (B) 6000 KW (C) 7600 KW (D) 8500 KW

Q 47.

At what rating in KWh the two sets will be equally economical to operate? (A) 5000 KWh (B) 7500 KWh (C) 75000 KWh (D) 50,000 KWh

Q 48.

Power factor is given by (A) KWh / KW (B) active power / reactive power (C) reactive power / active power (D) KW / KWh

Q 49. For the same cylinder dimensions and speed, which engine will produce least power? (A) Petrol engine



(B) Diesel engine (C) Super charged engine (D) All will produce same power Q 50.

For under water movement Submarines are powered by?

(A) Diesel engines (B) Air motors (C) Batteries (D) Steam accumulators Q 51.

Ships are generally powered by

(A) Diesel engines (B) Hydraulic turbines (C) Nuclear power plants (D) Steam accumulators

Q 52.

A turbojet aero plane has

(A) No blades (B) Two blades (C) Three blades (D) Four blades Q 53.

An interconnected system has the following plants

I

run off the river plant

II

Nuclear power plant

III

Steam power plant

IV

Hydro-electric plant with storage


V


Diesel engine plant

Which two plants can be exclusively used for base load? (A) I and II (E) II and III (F) II and IV (G) II and V Q 54.

Which plant can be used exclusively for peak load? (A) I (B) III (C) IV (D) V

Q 55.

Direct conversion of beat into electrical energy is possible through (A) Magneto hydrodynamic generators (B) Solar cells (C) Fuel cells (D) not possible

Q 56.

In a fuel cell electricity is produced by (A) Combustion of fuel in absence of oxygen (B) Oxidation of fuel (C) Thermionic action (D) Any of the above

Q 57. A certain plant has fixed cost of Rs 40,000 and a salvage value of Rs 4000 at the end of a useful life of 20 years The depreciated value of the plant at the end of 10 years will be least (interest rate being 6% compounded annually) when calculated by (A) Straight line method (B) Sinking fund method



(C) Diminishing value method

Q 58.

In the above problem the value will be highest when calculated by

(A) Straight line method (B) Sinking fund method (C) Diminishing value method Q 59.

Low power factor is usually not due to

(A) Incandescent lamp (B) Induction motors (C) Arc lamps (D) Fluorescent tubes Q 60.

Which type of plant has the least running cost per KWh of energy generated?

(A) Hydro-electric plant (B) Thermal power plant (C) Nuclear power plant (D) Diesel power plant

Q 61.

Base load plants have

(A) High capital cost, high operating cost and high load factor (B) High capital cost, low operating cost and high load factor (C) Low capital cost, low operating cost and low load factor (D) Low capital cost, high operation cost and high load factor


Q 62.


Which alternator will have more number of poles

(A) Coupled to hydraulic turbine (B) Coupled to steam turbine (C) Coupled to gas turbine (D) All will have same number of poles

Q 63.

Which alternator usually runs at slow speed as compared to others

(A) Coupled to gas turbine (B) Coupled to steam turbine (C) Coupled to hydraulic turbine (D) Coupled to diesel engine

Q 64. In a thermal power station of moderate size, the electrical power is generated at a voltage of (A) 115 V (B) 230 V (C) 440 V (D) 11 kV

Q 65. The resistance of the dry skin of human body, between the tip of the left hand finger and right hand finger, is of the order of (A) 100 ohms (B) 1000 ohms



(C) 10,000 ohms (D) 100,000 ohms

Q 66. If the resistance of dry skin of human body is 100,000 ohms, the resistance of the wet body will be (A) 100,000 ohms (B) 200,000 ohms (C) 5000,000 ohms (D) 5000 ohms

Q 67.

The effect of electric shock on human, body depends on

(A) Voltage (B) Current (C) Duration of contact (D) All of the above

Q 68.

A current of 10 mill amperes through human body

(A) Will cause mild sensation (B) Will affect muscle control (C) Will affect breathing (D) Will cause death

Q 69.

Death is almost certain when the current through human body is

(A) 10 mill amperes


(B) 20 mill amperes (C) 40 mill amperes (D) 100milliamperes

Q 70.

For extinguishing electrical fires

(A) Water should be used (B) Carbon dioxide fire extinguisher should be used (C) Foam type fire extinguisher should be used (D) Carbon tetrachloride fire extinguisher should be used

Q 71.

First aid for electric shock victim is

(A) Bandage (B) Massage (C) Pouring water on body (D) Artificial respiration




Multiple Choice Questions of Economics of Power Generation (168-182): Q 72.

When a power plant is not able to meet the demand of consumers it will resort to

(A) Penalizing high load consumers by increasing the charges for electricity (B) Power factor improvement at the generators (C) Efficient plant operation (D) Load shedding. Q 73.

Load shedding is possible through

(A) Voltage reduction (B) Frequency reduction (C) Switching off the loads (D) Any of the above.



Q 74. Which of the following power plants can generate power at unpredictable or uncontrollable times? (A) Wind power plant (B) Tidal power plant (C) Solar power plant (D) Any of the above.

Q 75.

Direct conversion of heat into electrical power is possible through

(A) Thermionic converter (B) Fuel cell (C) Batteries (D) all of the above.

Q 76.

In a fuel cell positive electrode is of

(A) Oxygen (B) Ammonia (C) Hydrogen (D) Carbon monoxide.

Q 77.

All of the following are sources of borrowing money EXCEPT

(A) Debentures (B) Bonds (C) Share (D) Fixed deposits.



Q 78. Ideally depreciated value of the plant plus the accumulation in the depreciation fund should be equal to (A) Salvage value (B) Obsolescence rate (C) Sinking fund (D) Original invested capital.

Q 79.

In power plants insurance cover is provided for

(A) Equipment only (B) Skilled workers only (C) Unskilled workers only (D) all of the above.

Q 80.

Debenture : Interest::

(A) Capital: Depreciation (B) Insurance: Mishap (C) Sinking fund: Amortization (D) Shares: Dividend.

Q 81.

Maximum demand tariff is generally not applied to domestic consumers because

(A) They cannot afford today (B) They consume less power (C) Their load factor is low



(D) Their maximum demand is low.

Q 82. How much must be deposited at the end of each year in a sinking fund for 15 years to accumulate Rs 1000 if interest is at 5 percent? (A) Rs 46.34 (B) Rs 54.55 (C) Rs 59.50 (D) Rs 60.00.

Q 83. If Rs. 50 were deposited at the end of each year for 12 years in a sinking fund earning 6%,the total accumulation would be (A) Rs 1000 (B) Rs 925.50 (C) Rs 843.50 (D) Rs 799.75.

Q 84.

An advantage of static capacitor for power factor improvement is

(A) Low losses (B) Little maintenance cost (C) Case in installation (D) All of the above.

Q 85. (A) Bonds

All of the following are repayable after some time EXCEPT



(B) Shares (C) Cash certificates (D) Fixed deposits

Q 86.

The usual value of

(A) Diversity factor is less than one and demand factor is more than one (B) Diversity factor more than one and demand factor is less than is one (C) Diversity factor as well as demand factor is less than demand (D) Diversity factor as well as demand factor is more than one.

Multiple Choice Questions of Economics of Power Generation (183-197) Q 87. The amount repaid to a person at the end of 15 years, who invests Rs 12,000 at 4 percent interest compounded annually, will be (A) Rs 12,400 (B) Rs 16,120 (C) Rs 21,612 (D) Rs 26,121. Q 88. What is the present worth of receiving Rs 1000 twenty years from now if money can earn 5% interest compounded annually? (A) Rs 376.93 (B) Rs 445.50 (C) Rs 500.00 (D) Rs 617.27.



Questions 185 to 187 refer to data given below:

Rs 10,000 are invested for 20 years at 6 percent.

Q 89.

The amount accumulated, when the interest is compounded annually will be

(A) Rs 27,020 (B) Rs 30,270 (C) Rs 32,070 (D) Rs 35,600.

Q 90.

The amount accumulated when the interest is compounded semi-annually will be

(A) Rs 32,070 (B) Rs 32,474 (C) Rs, 32,620 (D) Rs 32,888.

Q 91.

The amount accumulated when the interest is compounded monthly will be

(A) Rs 32,070 (B) Rs 32,620 (C) Rs 32,898 (D) Rs 33,100.

Q 92. As the load factor approaches unity, the shape of load duration curve will be nearly



(A) L shaped (B) Inverted T shaped (C) Triangular (D) Rectangular.

Q 93.

When maximum and average loads are equal, the load factor will be

(A) Zero (B) 0.01 (C) 0.5 (D) 1.0

Q 94.

Which of the following relation is incorrect?

(A) Capacity factor = Utilization factor x Load factor (B) Load factor x Maximum load = Average load (C) Demand factor x Connected load = Maximum demand (D) None of the above.

Q 95.

Capacity factor and load factor become identical when

(A) Peak load is equal to the capacity of the plant (B) Average load is half the capacity of the plant (C) Average load is same as peak load (D) Group diversity factor is equal to peak diversity factor.

Q 96.

A low utilization factor for a plant indicates that



(A) Plant is under maintenance (B) Plant is used for base load only (C) Plant is used for stand by purpose only (D) Plant is used for peak load as well as base load.

Questions 95 to 96 refer to the following data:

Power plants considered are I. Diesel II. Thermal III. Hydro IV. Nuclear. Q 97.

Plants in ascending order of capital cost per MW are

(A) I, II, III, IV (B) II, III, IV, I (C) III, IV, I, II (D) IV. III, I, II

Q 98.

Plants in descending order of their expected useful life are

(A) I, III, II, IV (B) II, I, III, IV (C) III, II, IV, I (D) IV, I, II, III.


Q 99.


Plants in ascending order of their operating cost per MWH generated are

(A) IV, I, II, III (B) III, II, IV, I (C) II, I, III, IV (D) I, III, II, IV

Q 100.

Sinking fund is

(A) Initial value - Salvage value (B) Capital cost - Operating cost (C) Periodical maintenance - Breakdown maintenance (D) Capital cost / Useful life.

1 2 3 4 5 6 7

D B A C C A D

21 22 23 24 25 26 27

A D A A C A D

41 42 43 44 45 46 47

A C C A B C C

61 62 63 64 65 66 67

B A C D D D D

81 82 83 84 85 86 87

D A C D B B C


8 9 10 11 12 13 14 15 16 17 18 19 20

D B C D D A B A B C C D B

28 29 30 31 32 33 34 35 36 37 38 39 40

A C A D C D A C A B B A B

48 49 50 51 52 53 54 55 56 57 58 59 60


B A C A A A D A B C B A A

Unit - 2 Q 101.

Load curve helps in deciding

(A) Sizes of the generation units (B) Total installed capacity of the plant (C) Operating schedule of generating units

68 69 70 71 72 73 74 75 76 77 78 79 80

A D D D D D D A A C D D D

88 89 90 91 92 93 94 95 96 97 98 99 100

A C C D D D D A C A C B A



(D) all of the above. Multiple Choice Questions of Economics of Power Generation (91-106): Q 102.

Major share of power produced is through

(A) Thermal power plants (B) Hydro electric power plants (C) Nuclear power plants (D) Diesel power plants Q 103.

Essential requirement of peak load plant

(A) It should be capable of standing quickly (B) It should be run at high speed (C) It should provide at high voltage (D) It should be small in size Q 104.

Which of the following plants is almost inevitably used as base load plant?

(A) Gas turbine plant (B) Diesel engine plant (C) Pumped storage plant (D) Nuclear power plant Q 105. A thermal power station was designed to bum coal containing 12% ash When the plant actually started operating coal having 22% ash was made available Which unit of the plant will need major modifications ? (A) Water treatment plant (B) Pulverizing unit (C) Ash handling unit (D) Cooling towers


Q 106.


Efficiency is secondary consideration in case of

(A) peak load plants (B) Base load plants (C) Both peak load and base load plants (D) None of the above

Q 107. Which of the following plants will take least time in starting from cold conditions to full load operation? (A) Nuclear power plant (B) Steam power plants (C) Hydro-electric plant (D) Gas turbine plant

Q 108.

During load shedding

(A) System voltage is reduced (B) System frequency is reduced (C) Some loads are switched off (D) System power factor is changed

Q 109.

For the same plant size, initial cost of which plant is the highest?

(A) Steam power plant (B) Diesel engine plant (C) Nuclear power plant



(D) Gas turbine plant

Q 110. A consumer takes a steady load of 200 kW at a power factor of 0.85 lagging for 8 hours per day and 315 days per annum. The annual payment under the tariff of Rs80 per annum per kA plus 10 cents per kWh will be (A) Rs 5040 (B) Rs 50,400 (C) Rs 69,200 (D) Rs 88,400

Questions 111 to 115 refer to the data given below: The estimated total annual operating cost and capital charges for two proposed power stations are given by the following expressions Annual cost of station A = Rs (600,000 + 3.0 kW + 0.015 kW hr) Annual cost of station B = Rs (750,000 + 5.0 kW + 0.014 kW hr) Where kW represents the capacity of the station and kWh represents the total annual output Load duration curve of the plant is shown in the figure given below

Q 111. (A) Station A (B) Station B

Which station may be selected for base load?



(C) Any of the above

Q 112.

Base load plant should be operated annually for

(A) 500 hrs (B) 1000hrs (C) 2000 hrs (D) 5000 hrs

Q 113.

The capacity of the base load plant should not be less than

(A) 3860 kW (B) 4180 kW (C) 5000 kW (D) 5500 kW Q 114.

Total kWh supplied by the plant is

(A) 10.l x 106 (B) 15 x 106 (C) 18 x 106 (D) 21.9 x 106

Q 115.

Total kWh to be supplied by base plant must be

(A) 19 .76 x 106 (B) 15.34 x 106 (C) 14.1 x 106 (D) 10.3 x 106



Q 116. For a load flow solution the quantities normally specified at a voltage controlled bus are: (A) P and Q (B) P and I V I (C) Q and I VI (D) P and

ᵟ

Q 117. For a 15-bus power system with 3 voltage controlled bus, the size of Jacobian matrix is (a) 11 x 11 (b)12 x 12 (c) 24 x 24 (d) 28 x 28. In the solution of load-flow equation, Newton-Raphon (NR) method is superior to the GaussSeidal (GS) method, because the (A) time taken to perform one iteration in the NR method is less when compared to the time taken in the GS method (B) number of iteration required in the NR method is more when compared to that in the GS method (C) number of iterations required is not independent of the size of the system in the NR method (D) convergence characteristic of the NR method are not affected by the selection of slack bus.

Q 118. Which one of the following matrices reveals the topology of the power system network ? (A) Bus incidence matrix (B) Primitive impedance matrix (C) Primitive admittance matrix (D) Bus impedance matrix. Q 119.

In load-flow analysis, the load at a bus is represented as



(A) a constant current drawn from the bus (B) a constant impedance connected at the bus (C) constant real and reactive powers drawn from the bus (D) a voltage-dependent impedance at the bus. (E) Q 120. In Gauss-Seidel method of power flow problem, the number of iterations may be re-duced if the correction in voltage at each bus is multiplied by (A) Gauss constant (B) Acceleration constant (C) Deceleration constant (D) Blocking factor.

Q 121. Consider the following statements : 1. It is easier to construct the YBus matrix as compared to ZBus. 2. ZBus is a full matrix while Ybus is sparse. 3. Y-bus can be easily modified whenever the network changes as compared to the ZBus. Which of these statements are correct ? (A) 1 and 2 (B) 2 and 3 (C) 1 and 3 (D) 1, 2 and 3.

Q 122.

In load flow studies of a power system, a voltage control bus is specified by

Real power and reactive power Real power and voltage magnitude Voltage and voltage phase angle



Reactive power and voltage magnitude. Q 123.

At slack bus, which one of the following combinations of variables is specified ?

(A) I V I,ᵟ (B) P, Q (C) P, I V I (D) Q, I V I.

Q 124. Consider the following quantities : 1. Real power 3. Power factor 5. Bus voltage magnitude 2. Reactive power 4. Input current 6. Bus voltage phase-angle. For the purpose of the load flow studies of a power system, each bus or node is associated with which one of the combinations of the above four quantities ? (A) 1, 3, 4 and 5 (B) 1, 2, 3 and 4 (C) 2, 3, 5 and 6 (D) 1, 2, 5 and 6. Q 125.

Normally ZBUS matrix is a (A) Null matrix (B) Full matrix (C) Sparse matrix (D) Unity matrix.

Q 126.

Gausss - Seidel iterative method can be used for solving a set of (A) Linear differential equations only



(B) Linear algebraic equations only (C) Both linear and nonlinear algebraic equations (D) Both linear and nonlinear differential equations Q 127. A power system consists of 300 buses out of which 20 buses are generator buses, 25 buses are the ones with reactive power support and 15 buses are the ones with fixed shunt capacitors. All the other buses are load buses. It is proposed to perform a load flow analysis for the system using Newton - Raphson method. The size of the Newton Raphson Jacobian matrix is (a) 553 x 553 (b) 540 x 540 (c) 555 x 555 (d) 554 x 554 Q 128.

In load - flow analysis, the load at a bus is represented as

(a) A constant current drawn from the bus (b) A constant impedance connected at the bus (c) Constant real and reactive powers drawn from the bus (d) A voltage - dependent impedance at the bus

Q 129.

Economic scheduling of generation is performed for a period of

(a) 1/2 hr (b) 24 hr (c) 1 sec (d) 1 week Q 130.

The input - output characteristic is plotted



(a) Fuel input Vs power output (b) Fuel input Vs time (c) Fuel rate Vs power output (d) Fuel rate Vs energy output Q 131.

Hear rate curve is plotted in

(a) k-cal/kwhr Vs KW (b) K-cal/hr Vs KW (c) k-cal/KW Vs Kw (d) K-cal Vs KW

Q 132.

Incremental production cost and incremental fuel cost are

(a) both the same (b) IPC > IFC (c) IPC < IFC (d) They are not related

Q 133.

In power system each bus is associated with how many quantities. (a) 4 (b) 3 (c) 5 (d) none

Q 134.

If real and reactive power components are specified then it is which type of bus. (a) PQ bus



(b) PV bus (c) slack bus (d) none Q 135. For which bus in the power system the voltage magnitude corresponding to the generation voltage and real power corresponding to its ratings are specified. (a) PQ bus (b) PV bus (c) slack bus (d) none Q 136. Which bus is in the power system is made to take additional real and reactive power to supply transmission losses. (a) PQ bus (b) PV bus (c) slack bus (d) none Q 137. For which bus we have to find out the voltage magnitude and phase angle of the bus through the load flow solution. (a) PQ bus (b) PV bus (c) slack bus (d) none Q 138. For which bus we have to find out the reactive power generation and phase angle of the bus through the load flow solution (a) PQ bus (b) PV bus



(c) slack bus (d) none

Q 139.

Diagonal element of the YBUS matrix is self admittance. (a) True (b) false

Q 140. I BUS= YBUS VBUS ,is the equation for n bus system, in this the matix size of YBUS is nXn. (A) True (B) False (C) None possible Q 141. I BUS= YBUS VBUS ,is the equation for n bus system, in this the matix size of YBUS is nX1. (a) True (b) False

Q 142.

I BUS= YBUS VBUS ,is the equation for n bus system, in this the matix size of YBUS is

(a) nXn (b) 1Xn (c) nX1 (d) 1X1 Q 143.

I BUS= YBUS VBUS ,is the equation for n bus system, in this the matix size of IBUS is

(A) nXn



(B) 1Xn (C) nX1 (D) 1X1 Q 144. I BUS= YBUS VBUS ,is the equation for n bus system, in this the matix size of VBUS is (a) nXn (b) 1Xn (c) nX1 (d) 1X1 Q 145.

YBUS is the nXn matrix, where n is the number of buses.

(a) true (b) false Q 146.

YBUS is the symmetric matrix


Diagonal element of the YBUS matrix is

(a) self admittance (b) transfer admittance (c) both (d) none Q 148.

off-Diagonal element of the YBUS matrix is

(a) self admittance (b) transfer admittance (c) both


(d) none Q 149.

ZBUS is a full matrix


For convenience which bus is considered as slack bus.

(a) First bus (b) last bus (c) middle bus (d) none. Q 151.

Slack bus is also called Swing bus


slack bus is also called Reference bus


Load bus is also called PV bus


Load bus is also called PQ bus


generator bus is also called PQ bus

(a) true (b) false



Q 156.


generator bus is also called PV bus


Load flow solution is the solution under which condition

(a) steady state condition (b) transient condition (c) both (d) none Q 158.

Load flow solution for power network can be worked out operation under

(a) balanced condition (b) unbalanced condition (c) both (d) none Q 159.

In power system each bus is associated with (a) four quantities (b) three quantities (c) five quantities (d) none

Q 160.

If real and reactive power components are specified then it is which type of bus. (a) load bus (b) generator bus (c) slack bus (d) none



Q 161. For which bus in the power system the voltage magnitude corresponding to the generation voltage and real power corresponding to its rating s are specified (a) load bus (b) generator bus (c) slack bus (d) none Q 162. Which bus is in the power system is made to take additional real and reactive power to supply transmission losses. (a) load bus (b) generator bus (c) slack bus (d) none Q 163. For which bus we have to find out the voltage magnitude and phase angle of the bus through the load flow solution. (a) load bus (b) generator bus (c) slack bus (d) none Q 164. For which bus we have to find out the reactive power generation and phase angle of the bus through the load flow solution (a) load bus (b) generator bus (c) slack bus (d) none Q 165. slack bus is in the power system is made to take additional real and reactive power to supply transmission losses.



(a) true (b) false Q 166. For generator bus we have to find out the voltage magnitude and phase angle of the bus through the load flow solution (a) True (b) False Q 167. For generator bus we have to find out the reactive power generation and phase angle of the bus through the load flow solution. a) true b) false Q 168. The voltage controlled bus is treated as a load bus in subsequent iteration when its Voltage limit is violated. (a) True (b) False Q 169. The voltage controlled bus is treated as a load bus in subsequent iteration when its:active power limit is violated. (a) true (b) false Q 170.

The load flow solution is always assured in case of Newton-Raphson method.

(a) True (b) False

Q 171. (a) true (b) false

The bus admittance matrix (Ybus) of a power system is Symmetric matrix.


Q 172.


The bus admittance matrix (Ybus) of a power system is Sparse matrix.

a) true b) false Q 173.

The bus admittance matrix (Ybus) of a power system is equal to Zbus matrix.

(a) True (b) False

Q 174. its:

The voltage controlled bus is treated as a load bus in subsequent iteration when

a) Voltage limit is voilated b) active power limit is voilated c) Reactive power limit is voilated d) Phase angle limit is voilated

Q 175.

The load flow solution is always assured in case of:

(a) Newton-Raphson method (b) Gauss method (c) Gauss -Seidel method (d) None of these method guarantees Q 176.

Compared to Gauss-Seidel method, Newton-Raphson method takes:

(a)less number of iterations (b)more number of iterations (c)equal number of iterations none of these


Q 177.


Compared to Gauss-Seidel method, Newton-Raphson method takes:

(a)less time per iteration (b)more time per iteration (c)equal time per iteration (d)none of these

Q 178.

At slack bus, which one of the following combination of variables is specified? (a) |V|, δ (b) P, θ (c) P, |V| (d) θ,|V|

Q 179. At Generator bus, which one of the following combination of variables is specified? (a) |V|, δ (b) P, |V| (c) P, θ (d) θ, |V| Q 180.

At Load bus, which one of the following combination of variables is specified?

(a) P, θ (b) θ, |V| (c) |V|, δ (d) P, Q Q 181. Which of the following quantity is associated with each bus or node for the purpose of load flow studies of a power system



(a) Real power (b) power factor (c) Input current (d) frequency

Q 182.

The bus admittance matrix (Ybus) of a power system is not

(a) Symmetric (b) a square matrix (c) a full matrix (d) generally having dominant diagonal elements Q 183. If a voltage controlled bus is treated as load bus, then which of the following limits would be violated? (a) Volatge (b) Active power (c) Reactive power (d) phase angle Q 184. For a 15-bus power system with 3 voltage controlled bus, the size of Jacobian matrix is (a) 11 X 11 (b) 12 X 12 (c) 24 X 24 (d) 28 X 28 Q 185.

The diagonal elements of a nodal admittance matrix are strengthen by adding



(a) Shunt inductances (b) shunt capacitances (c) loads (d) Generators

Q 186.

The load flow solution is always assured in case of:

a. Newton-Raphson method b. Gauss method c. Gauss-Seidel method d. None of these methods guarantees Q 187. In which of the following methods of load flow analysis the convergence of solution does not depend upon choice of slack bus a. Newton-Raphson method b. Gauss method c. Gauss-Seidel d. none of these

Q 188.

In aYbus matrix the diagonal element of each node is obtained by

a. Multiplying the admittances connected to it b. Adding the admittances connected to it c. Subtracting the admittances connected to it d. None of these



Q 189. Which fundamental law is applied at each node in a multi bus system to obtain Ybus matrix a. KVL b. KCL c. both d. one of the above Q 190.

In a large system of 100 nodes, the non-zero elements may be as small as a. 20% b. 22% c. 2% d. 9%

Q 191.

The Bus admittance matrix Ybus is a. Singular matrix b. Symmetric matrix c. Sparse matrix d. All of the above

Q 192.

In load flow studies of a power system, a voltage control bus is specified by a. Real power and reactive power b. Real power and voltage magnitude c. Voltage and voltage phase angle d. Reactive power and voltage magnitude

Q 193. In Gauss-Seidel method of power flow problem, the number of iterations may be reduced if the correction in voltage at each bus is multiplied by



a. Gauss constant b. Acceleration constant c. Deceleration constant d. Blocking factor Q 194.

Load flow study is carried out for

a. Fault calculations b. stability studies c. System planning d. Load frequency control Q 195.

Transient in electric circuits normally disappears within a time equal to

(a) 4 * time constant (b) 2* time constant (c) 8* time constant (d) time constant

Q 196. The convergence characteristic of the Netwon – Rophson method of solving a load flow problem is a) quadratic

b) linear

C) geometric

d) cubic

Q 197. 1. Load bus 2. PV bus(b) 3. Slack bus Q 198.

Buses for load flow studies are classified as


Q 199.

B. TECH. 4 Th YEAR 8Th

The principal information obtained from load flow studies in a power system are

1. magnitude and phase angle of the voltage at each bus

2. reactive and real power flows in each of the lines

3. total power loss in the network

4. transient stability limit of the system

Select the correct answer using the codes given below : (A) 1 and 2 (B) 3 and 4 (C) 1, 2 and 3

(D) 2 and 4

POWER SYSTEM



Q 200. Direction : The following two items consist of two statements, one labelled as Assertion ‘A’ and the other labelled as Reason ‘R’. You are to examine these two statements carefully and decide if the Assertion A and the Reason R are individually true and if so, whether the Reason is a correct explanation of the Assertion. Select your answers to these items using the codes given below.

Codes :

(A) Both A and R are true and R is the correct explanation of A (B) Both A and R are true but R is NOT the correct explanation of A (C) A is true but R is false (D) A is false but R is true Assertion (A) : Bus admittance matrix is a sparse matrix. Reason (R) : In load flow studies, one of the buses is take as a slack bus. Consider the following statements in respect of load flow studies in power systems : 1. Bus admittance matrix is a sparse matrix 2. Gauss-Seidel method is preferred over Newton-Raphson method for load flow studies 3. One of the buses is taken as slack bus in load flow studies

Which of the statements given above are correct ? (A) 1, 2 and 3 (B) 1 and 2 (C) 1 and 3 (D) 2 and 3


101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120

D A A D C A D C C C B C A D A B D D A C

121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140

B D B A D B B B C A A A B A A B C A B A

141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160


A A A C A A A A B A A A A B A B A A C A

161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180

A B C A B A B A B A B A A B B D A B A B

181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200

D A C C D A D A B B C D B B C C A B C C



Unit- 3 Q 201.

.

Q 202. The YBUS matrix of a 100-bus interconnected system is 90% sparse. Hence the number of transmission lines in the system must be (A) 450



(B) 500 (C) 900 (D) 1000

Q 203.

Q 204.

Q 204. 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 balancing power will be: (a) 30 MW leaving the node (b) 45 MW leaving the node

(c) 45 MW entering the node (d) 22.5 MW entering the node and 22.5 MW leaving the node. Q 205.

The loss coefficients for a two-bus system are given as follows:] (a) B11 = 0.02, B22 = 0.05, B12 = 0.01, B21 = 0.015. (b) B11 = 0.02, B22= 0.04, B12 = -0.01, B21 = - 0.001. (c)B11 = 0.03, B22= 0.005, B12 = - 0.001, B2I= - 0.001.

(d) B11= 0.03, B22 = 0.05, B12 = 0.001, B21 = - 0.001.



Q 206. For economic operation, the generator with highest positive incremental transmission • loss will operate at: (a) The lowest positive incremental cost of production (b) The lowest negative incremental cost of production (c) The highest positive incremental cost of production (d) None of the above.

Q 207.

The maximum permissible change in power frequency is (A) ±5 Hz (B) ±0.5 Hz (C) ±0.6 Hz (D) ± 0.05 Hz

Q 208. automatic generation and voltage regulation equipment is installed on each generator (A) Load frequency (B) Excitation voltage (C) Both A and B (D) None of these Q 209.

they take care of small changes in load demand (A) Without change in frequency and voltage (B) Without change in Power and voltage (C) Without change in Real Power and Reactive power (D) None of these


Q 210.


The change in load demand, this will change in alternator (A) Power angle (B) Excitation angle (C) Firing angle (D) None of these

Q 211.

The change in load demand, this will meet out by alternator (A) Excitation voltage (B) Speed of turbine (C) Both A and B (D) None of them

Q 212.

The change in load demand, this will change in alternator (A) Excitation voltage (B) Speed of turbine (C) Both A and B (D) None of them

Q 213. Maintain network frequency constant so that the powers so that the power station are satisfactorily parallel on the system run at the desired speed correct time is obtained from (A) Synchronoscope (B) Two lamp method (C) Three method (D) None of these Q 214.

Power angle will change in controlled formet



(A) Momentarily Small change in speed (B) Large change in speed (C) Medium change in speed (D) None of them Q 215.

power frequency control is slow due to (A) turbine and generator moment of inertia (B) turbine and generator troque (C) turbine and generator force (D) All of the above

Q 216.

Change in load demand can be identified as (A) slow varying changes in mean demand (B) fast random variations around the mean (C) A and B (D) None of them

Q 217.

What should be at question mark from picture (A) frequency

(B) Voltage

(C) Real power ?

(D) Speed Q 218.

Pilot piston is used for (A) Providing to help change in main piston


(B) Providing change in main Valve (C) Providing to flow in hydraulic oil (D) All of them Q 219.

These are part of LFC system (A) Fly ball speed governor (B) Hydraulic amplifier (C) Linkage mechanism (D) All of them

Q 220.

Fly ball speed governor is used for (A) frequency (B) Voltage (C) Real power (D) Speed

Q 221.

This modal may named as

(A) Turbine Model (B) Model of Speed Governing System (C) generator-load model (D) All of them Q 222.






(A) Turbine Model (B) Model of Speed Governing System (C) generator-load model (D) All of them

Give the answer all below questions



Q 224.

The value at position “ 1 ” in above modal (A) ∆ Pc ( s) (B) ∆ P D (s) (C) ∆ PG ( s) (D) ∆ F (s )

Q 225.

The value at position “ 2 ” in above modal (A) ∆ Pc ( s) (B) ∆ P D (s) (C) ∆ PG ( s) (D) ∆ F ( s )

Q 226.

The value at position “ 3 ” in above modal (A) ∆ Pc ( s) (B) ∆ Y E ( s) (C) ∆ PG ( s) (D) ∆ F (s )

Q 227.

The value at position “ 4 ” in above modal (A) ∆ Pc ( s) (B) ∆ P D (s) (C) ∆ PG ( s) (D) ∆ F ( s )

Q 228.

The value at position “ 6 ” in above modal (A) ∆ Pc ( s) (B) ∆ P D (s)



(C) ∆ PG ( s) (D) ∆ F (s ) Q 229.

The final value at above modal (A) ∆ Pc ( s) (B) ∆ P D (s) (C) ∆ PG ( s) (D) ∆ F ( s )

Q 230.

The input value at above modal (A) ∆ Pc ( s) (B) ∆ P D (s) (C) ∆ PG ( s) (D) ∆ F (s )

Q 231.

speed regulation of the governor (A) K1KC/K2 (B) K1KC K3/K4 (C) 1/K5 K4 (D) none of them

Q 232.

gain of speed governor (A) K1KC/K2 (B) K1KC K3/K4 (C) 1/K5 K4 (D) none of them



Q 233.


time constant of speed governor (A) K1KC/K2 (B) K1KC K3/K4 (C) 1/K5 K4 (D) none of them

Q 234.

The droop slope may define as (A)

−1 1 B+ R

( )

(B) B+

(C)

( 1R )

( R1 )

(D) None of them Q 235.

For 250 MW machine with an operating load of 125 MW. let the change in load ∂P be 1% for 1% change in frequency (scheduled frequency = 50 Hz). Then ∂f (A) 2.5 MW/Hz (B) 5.0 MW/Hz (C) 2.6 MW/Hz (D) 3.5 MW/Hz

Q 236.

For 250 MW machine with an operating load of 125 MW. let the change in load ∂P be 1% for 1% change in frequency (scheduled frequency = 50 Hz). Then ∂f (A) 0.001 pu MW/Hz (B) 0.01 pu MW/Hz (C) 0.1 pu MW/Hz



(D) 1 pu MW/Hz Q 237. A 100 MVA synchronous generator operates on full load at frequency of 50 Hz. The load is suddenly reduced to 50 MW. Due to time lag in governor system, the steam valve begins to close after 0.4 seconds. Given H = 5 kW-sec/KVA of generator capacity. Determine the change in frequency that occurs in this time. (A) 51 Hz (B) 50 Hz (C) 48 Hz (D) 49 Hz Q 238. A 100 MVA synchronous generator operates on full load at frequency of 50 Hz. The load is suddenly reduced to 50 MW. Due to time lag in governor system, the steam valve begins to close after 0.4 seconds. Given H = 5 kW-sec/KVA of generator capacity. Determine Excess power input to generator (A) 50 MW (B) 52 MW (C) 53 MW (D) 40 MW Q 239. A 100 MVA synchronous generator operates on full load at frequency of 50 Hz. The load is suddenly reduced to 50 MW. Due to time lag in governor system, the steam valve begins to close after 0.4 seconds. Given H = 5 kW-sec/KVA of generator capacity. Determine Kinetic energy stored in rotating parts of generator and turbine (A) 0.5 MW (B) 5.0 MW (C) 3.0 MW (D) 1.6 MW Q 240. A 100 MVA synchronous generator operates on full load at frequency of 50 Hz. The load is suddenly reduced to 50 MW. Due to time lag in governor system, the steam



valve begins to close after 0.4 seconds. Given H = 5 kW-sec/KVA of generator capacity. Determine Excess energy input to rotating parts in 0.4 sec (A) 21000 KW-Sec (B) 20000 KW-Sec (C) 19000 KW-Sec (D) Not calculated Q 241. Two generators rated 200 MW and 400 MW are operating in parallel. The droop characteristics of their governors are 4% and 5%, respectively from no load to full load. Assuming that the generators are operating at 50 Hz at no load, Assume free governor operation, how would a load of 600 MW be shared between them? (A) 230, 370 (B) 229, 371 (C) 231, 369 (D) Not calculated Q 242. Two generators rated 200 MW and 400 MW are operating in parallel. The droop characteristics of their governors are 4% and 5%, respectively from no load to full load. Assuming that the generators are operating at 50 Hz at no load, What will be the system frequency at this load? Assume free governor operation. (A) 51.59 Hz (B) 47.69 Hz (C) 48.99 Hz (D) 49.00 Hz Q 243.

This modal is showing (A) 1st order LFC modal (B) 2nd order LFC modal (C) Multiple order LFC modal




central economic dispatch computer is abbreviated (A) CEDC (B) CEC (C) EDC (D) None of them

Q 245.

synchronizing coefficient is (A)

(B)

(C)

|V 1||V 2| PX

|V 1||V 2| P r 1 X 12

|V 1||V 2| P

sin ⁡( δ 01−δ 01 )

sin ⁡( δ 1−δ 2)

(D) None of them Q 246. Maintain network frequency constant so that the powers so that the power station are satisfactorily parallel on the system run at the desired speed correct time is obtained from (A) Synchronoscope (B) Two lamp method (C) Three method (D) None of these Q 247.

Power angle will change in controlled format (A) Momentarily Small change in speed (B) Large change in speed (C) Medium change in speed


(D) None of them Q 248.

power frequency control is slow due to (A) turbine and generator moment of inertia (B) turbine and generator troque (C) turbine and generator force (D) All of the above

Q 249.

Two area control means (A) One power system are involved (B) two or more power system are involved (C) A and B (D) None of them

Q 250.

This equation shows

K sg 1+T sg s


This equation shows

Kt 1+T t s


This equation shows

K ps 1+T ps s




(A) Turbine Model (B) Model of Speed Governing System (C) generator-load model (D) All of them

201 202 203 204 205 206 207 208 209 210 211 212

D C C B C A

B C A A C C

221 222 223 224 225 226 227 228 229 230 231 232

B A C B A B C D D A B B

241 242 243 244 245 246 247 248 249 250 251 252

C B A A B A A A B C C C


213 214 215 216 217 218 219 220

A A A C A D D A

233 234 235 236 237 238 239 240


C A A B A A A B

Unit=4 Q 253.

Zero power factor method of an alternator is used to find its (A) field resistance (B) armature resistance (C) efficiency (D) voltage regulation

Q 254.

The power factor of an alternator is obtained from its (A) excitation (B) speed (C) load (D) none of the above

Q 255.

For parallel operation, alternators must have



(A) same speed (B) same kva rating (C) same voltage rating (D) none of the above Q 256.

For alternation having fractional pitch of 5/6 the coil span is (A) 90° (B) 120° (C) 150° (D) 180°

Q 257.

Fractional pitch to eliminate 7th harmonic from alternator emf is (A) 7/6 (B) 6/7 (C) 6/5 (D) 3/5

Q 258. Consider the following statements about a three-phase synchronous generator synchronized to an infinite bus when its mechanical input is increased gradually with field current held constant: 1

The power factor of the current supplied becomes more lagging

2

The power factor of the current supplied improves

3

The power factor remains unity

4

The load angle is increased

Of these statements (A) 1 alone is correct (B) 2 alone is correct



(C) 2 and 4 are correct (D) 3 and 4 are correct Q 259. A 3-phase synchronous generator, with its armature resistance and the leakage reactance being neglected, is synchronized to an infinite bus and its field excitation is kept constant thereafter Now the machine is loaded by Supplying mechanical input to the shaft so that the load-angle δ reaches a value of 60° Under this condition, the operating power-factor would be (A) 0.866 leading (B) 0.866 lagging (C) 0 .5 leading (D) 0.5 lagging Q 260. A round rotor synchronous generator has a leakage reactance of 10%, armature reaction reactance of 90% and negligible armature resistance with the machine initially running at rated speed and terminal voltage of 1.0 pu, a 3-phase short-circuit is applied The sustained armature current will be (A) 1.25 pu (B) 1.11 pu (C) 1.0 pu (D) 0.9 pu Q 261. Following a sudden short-circuit at the terminals of a 3-phase unloaded synchronous generator, the initial effect of the pole-face damper windings, is to (A) establish the armature flux through the direct-axis magnetic circuit of the machine (B) allow only partial linkage of the armature flux with the main field winding (C) confine the armature flux to completely link the damper winding (D) repel the armature flux and confine it to the leakage flux path in the air-gap Q 262. In a synchronous generator operating at zero pf lagging, the effect of armature reaction is



(A) magnetizing (B) demagnetizing (C) cross-magnetizing (D) both magnetizing and cross-magnetizing Q 263. Which of the following limit the reactive power output of a synchronous generator ? 1

Armature current

2

Field current

3

Load angle

4

Prime mover input

Select the correct answer using the codes given below: Codes (A) 1 and 2 (B) 2 and 3 (C) 3 and 4 (D) 1 and 4 Q 264.

The steady-state stability limit of a synchronous generator can be increased by (A) an increase in its reactance (B) an increase in the excitation of the machine (C) a decrease in the moment of inertia of the machine (D) an increase in the moment of intertia of the machine

State whether the following statements related to Synchronous Generator are true (T) or false (F): Q 265.

Synchronous reactance can be determined from open circuit and short circuit tests



(A) TRUE (B) FALSE (C) Not Possible (D) None of these Q 266.

Voltage regulation can be determined by synchronous impedance method (A) TRUE (B) FALSE (C) Not Possible (D) None of these

Q 267. Percentage resistance is the resistance drop at rated current and frequency expressed as the percentage of the rated voltage (A) TRUE (B) FALSE (C) Not Possible (D) None of these Q 268. MMF method for regulation does not use data available from open circuit and short circuit tests (A) TRUE (B) FALSE (C) Not Possible (D) None of these Q 269.

In short-pitch windings fractional number of slots per pole can be used (A) TRUE (B) FALSE



(C) Not Possible (D) None of these Q 270.

One of the advantage of short pitch windings is saving in copper (A) TRUE (B) FALSE (C) Not Possible (D) None of these

Q 271.

Large scale power generation is done by synchronous generators (A) TRUE (B) FALSE (C) Not Possible (D) None of these

Q 272.

The angle between Eg and Vt is called the power angle (A) TRUE (B) FALSE (C) Not Possible (D) None of these

Q 273.

Synchronous reactance is determined by synchronous reactance method (A) TRUE (B) FALSE (C) Not Possible (D) None of these

Q 274. Synchronous generator must operate at the correct speed as it determines the frequency since the number of poles is fixed for any given machine



(A) TRUE (B) FALSE (C) Not Possible (D) None of these Q 275. The voltage regulation of an ac generator is defined as the rise in voltage when the load is reduced from full-rated load value to zero, speed and field current remaining constant (A) TRUE (B) FALSE (C) Not Possible (D) None of these Q 276.

Armature reaction in an alternator affects generated voltage/phase (A) TRUE (B) FALSE (C) Not Possible (D) None of these

Q 277.

Armature reaction in an alternator is magnetizing at lagging loads (A) TRUE (B) FALSE (C) Not Possible (D) None of these

Q 278.

Maximum demand on a power plant is (A) The greatest of all "short time interval averaged" demand during a period (B) Instantaneous maximum value of KVA supplied during a period



(C) Both (a) or (b) (D) None of the above Q 279.

In an alternator, the frequency per revolution is equal to (A) Number of poles (B) Number of pairs of poles (C) Number of armature conductors (D) Forty

Q 280. Squirrel cage bars placed in the rotor pole faces of an alternator help reduce hunting (A) Above synchronous speed only (B) Below synchronous speed only (C) Above and below synchronous speeds both (D) None of the above Q 281.

Stationary alternator should not be connected to live bus-bars because it (A) Is likely to run as synchronous motor (B) Will get short – circuited (C) Will decrease bus - bar voltage though momentarily (D) Will disturb generated emf's of other alternators connected in parallel

Q 282. With a unity load p of an alternator is (A) Distortional (B) Magnetizing (C) Demagnetizing (D) Nominal

f, the effect of armature reaction on the main field flux


Q 283.


At lagging loads, armature reaction in an alternator is (A) Cross-magnetising (B) Demagnetizing (C) Non-effective (D) Magnetizing

Q 284. The frequency of voltage generated by an alternator having 4 poles and rotating at 1800 rpm is (A) 60 Hz (B) 7200 Hz (C) 120 Hz (D) 450 Hz Q 285.

The main disadvantages of using short pitch winding in alternators is that it (A) Reduces harmonics in the generated voltage (B) Reduces the total voltage around the armature coils (C) Produces asymmetry in the three phase windings (D) Increases Cu of end connections

Q 286.

Zero power factor method of an alternator is used to find its (A) Efficiency (B) Voltage regulation (C) Armature resistance (D) Synchronous impedance

Q 287.

Armature reaction in an alternator mainly affects (A) Rotor speed



(B) Terminal voltage per phase (C) Frequency of armature current (D) Generated voltage per phase Q 288.

The effect of increasing air gap length in the induction motor will increase the (A) Power factor (B) Speed (C) Magnetizing current (D) Air gap flux

Q 289.

The principle of operation of a 3 phase induction motor is most similar to that of a (A) Synchronous motor (B) Repulsion start induction motor (C) Transformer with a shorted secondary (D) Capacitor start, induction run motor

Q 290. Squirrel cage bars placed in the rotor pole faces of an alternator help reduce hunting (A) Above synchronous speed only (B) Below synchronous speed only (C) Above and below synchronous speeds both (D) None of the above Q 291.

The stationary alternator should not be connected to live bus-bars because it (A) Is likely to run as synchronous motor (B) Will get short – circuited (C) Will decrease bus - bar voltage though momentarily



(D) Will disturb generated emf's of other alternators connected in parallel Q 292. With a unity load pf, the effect of armature reaction on the main field flux of an alternator is (A) Distortional (B) Magnetizing (C) Demagnetizing (D) Nominal Q 293.

At lagging loads, armature reaction in an alternator is (A) Cross-magnetising (B) Demagnetizing (C) Non-effective (D) Magnetizing

Q 294. The frequency of voltage generated by an alternator having 4 poles and rotating at 1800 rpm is (A) 60 Hz (B) 7200 Hz (C) 120 Hz (D) 450 Hz Q 295.

The main disadvantages of using short pitch winding in alternators is that it (A) Reduces harmonics in the generated voltage (B) Reduces the total voltage around the armature coils (C) Produces asymmetry in the three phase windings (D) Increases Cu of end connections

Q 296.

Zero power factor method of an alternator is used to find its



(A) Efficiency (B) Voltage regulation (C) Armature resistance (D) Synchronous impedance Q 297.

Armature reaction in an alternator mainly affects (A) Rotor speed (B) Terminal voltage per phase (C) Frequency of armature current (D) Generated voltage per phase

Q 298.

The effect of increasing air gap length in the induction motor will increase the (A) Power factor (B) Speed (C) Magnetizing current (D) Air gap flux

Q 299.

The principle of operation of a 3 phase induction motor is most similar to that of a (A) Synchronous motor (B) Repulsion start induction motor (C) Transformer with a shorted secondary (D) Capacitor start, induction run motor

Q 300.

Two alternators are paralleled___ (A) So that one isn't overworked



(B) Because of a rising load demand (C) To ease the work load (D) Because of the declining load demand Q 301.

To parallel alternators, it's necessary to match___ (A) Voltages (B) Frequencies (C) Voltages & frequencies (D) Voltages, frequencies, & instantaneous polarities

Q 302.

The output voltage of an alternator is controlled by___ (A) Adjusting the prime mover (B) Adjusting the direct current of the field circuit (C) Synchronizing lamps (D) A synchroscope

Q 303. Alternators shouldn't be paralleled unless the synchronizing lamps are lighting & dimming ___ (A) In rotation (B) In reverse rotation (C) In unison (D) Alternately Q 304. Three lights flashing rapidly in unison while paralleling alternators means that ____ (A) The machines are not polarized (B) The phase sequences are wrong (C) The paralleling switch should be closed



(D) The frequencies differ by a large amount Q 305.

The most reliable method of synchronizing alternators is to use __________ (A) A synchroscope (B) The three dark method (C) The three light method (D) The two bright, one dark method

Q 306. When the pointer of a synchroscope is stationary & points upward during the paralleling operation, the ____ (A) Alternators are in synchronism (B) Alternators are not in synchronism (C) Incoming alternator frequency is too slow (D) Incoming alternator frequency is too fast Q 307. The division of load between alternators operating in parallel is accomplished by changing the (A) Field excitation (B) Speed of the prime movers (C) Power factor of the load (D) Machine characteristics Q 308.

What is the V/Hz ratio? (A) To develop rated torque (B) To develop rated Current (C) To develop rated Power (D) To develop rated frequency

Q 309. The power output of an alternator is 40 kW and KVAR component is – 25.What will be the value of tanφ (φ being the power factor angle) ?



(A) 0 .625 lagging (B) 0 .625 leading (C) 0.375 lagging (D) 0 .375 leading Q 310. A 120 MW turbo alternator is supplying power to 80 MW load at pf lagging Suddenly the steam supply to the turbine is cut off and the alternator remains connected to the supply network and the field supply also remains on What will happen to the alternator ? (A) The stator winding of the alternator will get burnt (B) The rotor winding of the alternator will get burnt (C) The alternator will continue to run as a synchronous motor rotating in the same direction (D) The alternator will continue to run as a synchronous motor rotating in the opposite direction Q 311. The figure shows the characteristics of an alternator. Which curve represents synchronous impedance?

(A) curve A (B) curve B (C) curve C



(D) curve D Q 312.

In the above figure (Figure of Question 49) which curve represents short circuit ? (A) curve A (B) curve B (C) curve C (D) curve D

Q 313.

In the above figure which curve represents open circuit voltage ? (A) curve A (B) curve B (C) curve C (D) curve D

Q 314. For a peripheral speed of 314 m/s, a 2 pole cylindrical machine will have maximum diameter of (A) 255 cm (B) 235 cm (C) 200 cm (D) 170 cm Q 315. The rotor of the salient pole alternator has 24 poles. The number of cycles of emf in one revolution would be (A) 24 (B) 12 (C) 6 (D) 4 Q 316. Two alternators A and B are sharing an inductive load equally excitation of alternator A is increased

If the



(A) alternator B will deliver more current and alternator A will deliver less current (B) alternator B will deliver less current and alternator A will deliver more current (C) both will continue to share load equally (D) both will deliver more current Q 317.

Desirable feature for the parallel operation of two alternators is (A) both should have same resistance (B) both should have same reactance (C) both should have less of resistance as compared to synchronous reactance (D) both should have more of resistance as compared to synchronous reactance

Q 318.

Alternators used in aircraft systems usually have frequency of (A) 25 Hz (B) 50 Hz (C) 100 Hz (D) 400 Hz

Q 319.

High frequency on aircraft alternators is selected in order to (A) free the systems from external disturbance (B) compensate for high speeds (C) compensate for high altitudes (D) reduce the bulk

Q 320. A 20 pole ac generator rotates at 600 rpm seconds per cycle is (A) 0.009 (B) 0. 004 (C) 0 .008

The periodic time of current in



(D) 0. 01 Q 321.

What kind of rotor is most suitable for turbo alternators ? (A) salient pole type (B) non-salient pole type (C) both (A) and (B) above (D) None of the above

Q 322. The synchronizing power developed in one of the alternators, when two alternators are running in parallel, will load the same alternator in which it is developed and reduce its speed (A) True (B) False (C) None of these (D) This is wrong Q 323. If the input to the prime mover of an alternator is kept constant but the excitation is changed then the (A) reactive component of the output is changed (B) active component of the output is changed (C) power factor of load remains constant (D) None of them Q 324. If two machines are running in synchronism and the voltage of one machine is suddenly increased (A) the machines will burn (B) both machines will stop (C) synchronising torque will be produced to restore further synchronism (D) None of them



Q 325. In an alternator, at 0.8 lagging power factor, the generated voltage per phase is 240 V to give a rated terminated voltage ' V ' . If the power factor of load increases to unity, the generated voltage per phase must be (A) 260 V (B) 250 V (C) 240 V (D) 225 V Q 326.

The advantage of salient poles in an alternator is (A) reduce noise (B) reduced windage loss (C) adoptability to low and medium speed operation (D) reduce bearing loads and noise

Q 327. Magnetization curves for no load and full load unity power factor are shown in figure below Which is the magnetization curve for full load 0 8 power factor?

(A) curve A (B) curve B (C) curve C (D) curve D



Q 328. At a particular instant a turbo alternator is generating 80 MW at 0.8 power factor lagging Now if the steam supply valve to the steam turbine is further opened and the excitation is not changed (A) the speed of the alternator will increase but kW delivered will remain unchanged (B) the speed of the alternator will increase and kW delivered will also increase (C) the speed of the alternator will remain unchanged but it can meet more kW demand (D) the speed of the alternator will remain unchanged but it will deliver more kVA Q 329. Two alternators A and B are sharing a resistive load (P f = 1 ) equally. Now if the excitation of alternator A is increased (A) alternator A will become lagging and alternator B will become leading (B) alternator A will become leading and alternator B will become lagging (C) both alternators will continue to operate on unity power factor (D) both alternators will operate on lagging power factor Q 330.

The advantage of providing damper winding in alternators is (A) elimination of harmonic effects (B) provide a low resistance path for the currents due to unbalancing of voltage (C) oscillations are provided when two alternators operate in parallel (D) All of the above

Q 331. When two alternators are running in exactly synchronism, the synchronising power wil be (A) zero (B) sum of the output of two (C) unity (D) 0.707 Q 332.

Questions 70 to 72 refer to the figure given below :



Q 333. Load characteristic curves for an alternator are shown. The curves are drawn for 0. 8 pf lagging, 0.8 pf leading, 0.7 p f leading and 0. 9 pf lagging. Which curve represents the characteristics for 0 .8 p f leading ? (A) curve A (B) curve B (C) curve C (D) curve D Q 334.

Which curve represents the data for 0.8 p .f lagging ? (A) curve A (B) curve B (C) curve C (D) curve D

Q 335.

Which curve represents the data for 0.9 p f lagging ? (A) curve A (B) curve B (C) curve C (D) curve D



Q 336. The balanced short circuit current of a three phase alternator is 25 amperes at 1500 rpm For the same field current, the balanced short current at 1400 rpm will be (A) 18.00A (B) 27 . 00 A (C) 20.00 A (D) 28.28A Q 337. A three phase alternator has a phase sequence of RYB for its three output voltages, for clockwise rotation Now if the alternator is rotated anticlockwise, the phase sequence will be (A) RYB (B) RBY (C) BYR (D) none of the above Q 338. In a synchronous machine, if the field flux axis is ahead of the armature field axis, in the direction of rotation, the machine working as (A) asynchronous motor (B) asynchronous generator (C) synchronous motor (D) synchronous generator Q 339. In synchronous alternator, which of the following coils will have emf closer to sine waveform ? (A) concentrated winding in full pitch coils (B) concentrated winding in short pitch coils (C) distributed winding in full pitch coils (D) distributed winding in short pitch coils.



Q 340. An alternator has rated field current of 4 A. The alternator develops 180 V while drawing a field current of 2 A at 750 rpm. If the field current is made 4 A at 750 rpm generated voltage could be (A) 400 V (B) 380 V (C) 60V (D) 330 V. Q 341. The armature reaction of an alternator will be completely magnetizing in case the load power factor is (A) unity (B) 0.707 (C) zero lagging (D) zero loading. Q 342.

Which of the following is not an integral part of synchronous generator system ? (A) prime mover (B) distribution transformer (C) excitation system (D) protection system.

Q 343.

For turbo generators the range of excitation voltage is (A) 10 to 20 V (B) 30 to 100 V (C) 100 to 800 V (D) 1000 to 1800 V.

Q 344.

In case of low speed hydrogenerators, the short circuit ratio is usually (A) 0.1 to 0.5



(B) 0.5 to 0.6 (C) 0.6 to 1.0 (D) 1.0 to 1.5. Q 345. The permissible duration for which a generator of rated frequency 50 Hz can run at 46 Hz is (A) zero (B) one cycle (C) one second (D) one minute. Q 346.

The permissible duration in supply . frequency is (A) ± 2 % (B) ± 5 % (C) ± 10 % (D) ± 25 %.

Q 347.

84. The regulation of an alternator is likely to be negative in case of (A) high speed alternators (B) slow speed alternators (C) lagging power factor of the load (D) leading power factor of the load.

Q 348.

Questions 85 to 88 refer to the data given below:

A phase, 50 Hz, 6600 V, alternator is rated at 6600 kW at 0.8 power factor and a full load efficiency of 90%. Q 349.

85. kVA is rating of the alternator is (A) 750 kVA



(B) 7500 kVA (C) 75000 kVA (D) 750000 kVA. Q 350.

The current rating of the alternator is (A) 65.63 A (B) 656.3 A (C) 6563 A (D) 65630 A.

Q 351.

The input to the alternator is (A) 666.6 kW (B) 6666 kW (C) 66660 kW (D) 666,600 kW.

Q 352. If the input. to an alternator remains unaltered, but excitation is changed then which of the following will not change ? (A) kVA output (B) kW output (C) power factor (D) all of the above.


253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272

D C C C B B B B B B B B A A A B A A A A

273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292

A A A A B A A C B A D A B B D C C C B A

293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312


D A B B D C C B D B C C A A B B D C A C

313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332

D C B B C D D D B A A C D C D C A D A C

333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352

A B C B D D D D B C D C A D B C B B A B



Unit - 5 Q 353.

SCO full name (A) Security constrained power system optimization (B) Security constrained optimization (C) System constrained power system optimization (D) None of these

Q 354.

System security involves (A) Economizing on fuel cost and (B) Minimizing emission of gases (C) Both above (D) None of these

Q 355.

EMS say in full name (A) Energy management system (B) Energy management security (C) Economic management system (D) None of these

Q 356. System security can be said to comprise of three major functions that are used in an energy control centre: (A) system monitoring (B) Contingency Analysis



(C) Corrective action analysis. (D) All of above Q 357.

System monitoring system supplies some info which helps (A) Power system operators (B) Power system Dispatcher (C) Both A and B (D) None of them

Q 358.

System monitoring system supplies some info which contains (A) Real time basis as load change (B) Real time basis as Generation change (C) Both A and B (D) None of them

Q 359.

SCADA is known as (A) Supervision Control And Data Access (B) Supervisory Control And Data Access (C) Supervisory Communication And Data Acquisition (D) Supervisory Control And Data Acquisition

Q 360.

State estimation means (A) Best estimation of data (B) Best economy data (C) SCADA data (D) None of them

Q 361.

contingency analysis may define (A) forecasting possible power system Dispatch


(B) forecasting possible system troubles (C) forecasting possible system Requirement (D) none of them Q 362.

Corrective action analysis means (A) Solve Predicted a serious problem (B) Maintenance (C) Both A and B (D) None of these

Q 363.

Energy Management System is contains (A) Secure, (B) Correctable emergency (C) Restoration (D) All of above

Q 364.

SECURITY ANALYSIS may divided into (A) Security assessment (B) Security control (C) Both of above (D) Not divided

Q 365.

Security assessment involves (A) system monitoring (B) contingency analysis (C) Both of above (D) Not divided

Q 366.

Power system static security Level are



(A) 4 (B) 5 (C) 6 (D) 2 Q 367.

Power system static security Level 6th is (A) Alert (B) Correctable emergency (C) Non-Correctable emergency (D) Restorative

Q 368.

Power system static security Level 5th is (A) Correctively secure (B) Alert (C) Correctable emergency (D) Non-Correctable emergency

Q 369.

Power system static security Level 4th is (A) Correctively secure (B) Alert (C) Correctable emergency (D) Non-Correctable emergency

Q 370.

Power system static security Level 3rd is (A) Correctively secure (B) Alert (C) Correctable emergency (D) Non-Correctable emergency



Q 371.


Power system static security Level 2nd is (A) Correctively secure (B) Alert (C) Correctable emergency (D) Non-Correctable emergency

Q 372.

Power system static security Level 1st is (A) Correctively secure (B) Secure (C) Correctable emergency (D) Non-Correctable emergency

Q 373.

Power system static security Level is not (A) Correctable emergency (B) Non-Correctable emergency (C) Restorative (D) EMS

Q 374.

OPF full name (A) Optimal power flow (B) Operational power flow (C) Optimal power field (D) None of them

Q 375. As the load factor approaches unity, the shape of load duration curve will be nearly (A) L shaped (B) Inverted T shaped


(C) Triangular (D) Rectangular. Q 376.

contingency analysis may define (A) forecasting possible power system Dispatch (B) forecasting possible system troubles (C) forecasting possible system Requirement (D) none of them

Q 377.

Corrective action analysis means (A) Solve Predicted a serious problem (B) Maintenance (C) Both A and B (D) None of these

Q 378.

Energy Management System is contains (A) Secure, (B) Correctable emergency (C) Restoration (D) All of above

Q 379.


Q 380.

Generation Shift factor written as



(A) α li=

∆fl ∆ PGi

(B) α li=

∆ PGi ∆fl


(C) Both A and B (D) None of these Q 381.

contingency selection may also known as (A) contingency screening (B) Solve Predicted a serious problem (C) Security control (D) Correctable emergency

Q 382.

Effective counter Measures to prevent or contain voltage Instability (A) Generator terminal voltage shourd be raised. (B) Generator transformer tap value may be increased (C) Load-end OLTC (on-load tap changer) should be suitably used (D) All of them

Q 383.

Effective counter Measures to prevent or contain voltage Instability (A) Q-injection should be carried out at an appropriate location. (B) Load-end OLTC (on-load tap changer) should be suitably used. (C) For under voltage conditions, strategic load shedding should be resorted (D) All of them

Q 384.

Effective counter Measures to prevent or contain voltage Instability (A) Q-injection should be carried out at an appropriate location. (B) Load-end OLTC (on-load tap changer) should be suitably used.



(C) Both A and B (D) None of all Q 385.

Effective counter Measures to prevent or contain voltage Instability (A) Load-end OLTC (on-load tap changer) should be suitably used. (B) For under voltage conditions, strategic load shedding should be resorted (C) Both A and B (D) None of all

Q 386.

Effective counter Measures to prevent or contain voltage Instability (A) Generator terminal voltage should be raised. (B) Generator transformer tap value may be increased (C) Q-injection should be carried out at an appropriate location (D) All of them

Q 387.

When a power plant is not able to meet the demand of consumers it will resort to (A) Penalizing high load consumers by increasing the charges for electricity (B) power factor improvement at the generators (C) efficient plant operation (D) Load shedding.

Q 388.

Load shedding is possible through (A) voltage reduction (B) frequency reduction (C) switching off the loads (D) All of the above.

Q 389. Which of the following power plants can generate power at unpredictable or uncontrollable times?



(A) Wind power plant (B) Tidal power plant (C) Solar power plant (D) All of the above Q 390.

Direct conversion of heat into electrical power is possible through (A) thermionic converter (B) fuel cell (C) batteries (D) all of the above.

Q 391.


Q 392.


Q 393.

Power system static security Level 1st is (A) Correctively secure (B) Secure (C) Correctable emergency (D) Non-Correctable emergency


Q 394.


Effective counter Measures to prevent or contain voltage Instability (A) Q-injection should be carried out at an appropriate location. (B) Load-end OLTC (on-load tap changer) should be suitably used. (C) For under voltage conditions, strategic load shedding should be resorted (D) All of them

Q 395.

Effective counter Measures to prevent or contain voltage Instability (A) Q-injection should be carried out at an appropriate location. (B) Load-end OLTC (on-load tap changer) should be suitably used. (C) Both A and B (D) None of all

Q 396.


Q 397.

Generation Shift factor written as (A) α li=

∆fl ∆ PGi

(B) α li=

∆ PGi ∆fl

(C) Both A and B (D) None of these Q 398.

Voltage collapse is the process is happen due to (A) System phase sequence is changed



(B) Sudden change in load (C) A and B both (D) None of them Q 399. 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 (A) 400 MW (B) 720 MW (C) 500 MW (D) 600 MW Q 400. A three-phase, 33kV oil circuit breaker is rated 1200A, 2000MVA, 3s. The symmetrical breaking current is (A) 1200A (B) 3600A (C) 35kA (D) 104.8Ka Q 401.

Effective counter Measures to prevent or contain voltage Instability (A) Generator terminal voltage should be raised. (B) Generator transformer tap value may be increased (C) Load-end OLTC (on-load tap changer) should be suitably used (D) All of them

Q 402.

Effective counter Measures to prevent or contain voltage Instability (A) Q-injection should be carried out at an appropriate location. (B) Load-end OLTC (on-load tap changer) should be suitably used. (C) For under voltage conditions, strategic load shedding should be resorted



(D) All of them Q 403.

Effective counter Measures to prevent or contain voltage Instability (A) Q-injection should be carried out at an appropriate location. (B) Load-end OLTC (on-load tap changer) should be suitably used. (C) Both A and B (D) None of all

Q 404.

Effective counter Measures to prevent or contain voltage Instability (A) Load-end OLTC (on-load tap changer) should be suitably used. (B) For under voltage conditions, strategic load shedding should be resorted (C) Both A and B (D) None of all

Q 405.

Effective counter Measures to prevent or contain voltage Instability (A) Generator terminal voltage should be raised. (B) Generator transformer tap value may be increased (C) Q-injection should be carried out at an appropriate location (D) All of them

Q 406.

When a power plant is not able to meet the demand of consumers it will resort to (A) Penalizing high load consumers by increasing the charges for electricity (B) power factor improvement at the generators (C) efficient plant operation (D) Load shedding.

Q 407.

Load shedding is possible through (A) voltage reduction (B) frequency reduction



(C) switching off the loads (D) All of the above. Q 408. Which of the following power plants can generate power at unpredictable or uncontrollable times? (A) Wind power plant (B) Tidal power plant (C) Solar power plant (D) All of the above Q 409.

Direct conversion of heat into electrical power is possible through (A) thermionic converter (B) fuel cell (C) batteries (D) all of the above.

Q 410.


Q 411.


Q 412.

Power system static security Level 1st is



(A) Correctively secure (B) Secure (C) Correctable emergency (D) Non-Correctable emergency Q 413.

Effective counter Measures to contain voltage Instability (A) Q-injection should be carried out at an appropriate location. (B) Load-end OLTC (on-load tap changer) should be suitably used. (C) For under voltage conditions, strategic load shedding should be resorted (D) All of them

Q 414.

Effective counter Measures to prevent voltage Instability (A) Q-injection should be carried out at an appropriate location. (B) Load-end OLTC (on-load tap changer) should be suitably used. (C) Both A and B (D) None of all

Q 415.

SECURITY ANALYSIS may disuses in part (A) Security assessment (B) Security control (C) Both of above (D) Not divided

353 354 355 356 357

A C A D C

373 374 375 376 377

D A A B C

393 394 395 396 397

B D C C A

413 414 415

D C C


358 359 360 361 362 363 364 365 366 367 368 369 370 371 372

C D A B C D C C C D D C B A B

378 379 380 381 382 383 384 385 386 387 388 389 390 391 392

D C A A D D C C D D C D A B A


398 399 400 401 402 403 404 405 406 407 408 409 410 411 412

C B C D D C C D D C D A B A B

Objective Type Questions for -Power System Operation and Control Final Year

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