# MCQ in Power Plant Engineering Part 2 | REE Board Exam

(Last Updated On: October 3, 2020) This is the Multiple Choice Questions Part 2 of the Series in Power Plant Engineering as one of the Electrical Engineering topic. In Preparation for the REE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Electrical Engineering field, Electrical Engineering Books, Journals and other Electrical Engineering References.

#### Continue Practice Exam Test Questions Part 2 of the Series

Choose the letter of the best answer in each questions.

51.  What do you call the protective angle between the Overhead ground wire and the power cable in the Transmission tower

a. surge angle

b. clearing angle

c shielding angle

d. arcing angle

Solution:

52.  Disconnecting switch is provided for proper protection of electric substations and power plant. What is its main function.

a. for protection of circuit breaker

b. to break the system under fault

c. for complete isolation

d. for maintenance purpose

Solution:

53.  The highest magnitude of fault current will determine the size of _________, while the lowest magnitude will determine the size of_____________.

a. circuit breaker, relay

b. circuit breaker, isolator

c. fuse, relay

d. relay, circuit breaker

Solution:

54.  The PTs of a 220 kV transmission line have ratio of 132.76 kV: 66.375 V and are connected wye-wye. A voltmeter connected line to ground reads 66 V, what is the transmission line voltage?

a. 228.63 kV

b. 223.15 kV

c. 220.10 kV

d. 225.25 kV

Solution:

55.  The transfer bus scheme has the following characteristics EXCEPT one. Which one of this?

a.  It allows the disconnection of circuit breakers for maintenance without Interrupting the service

b.  It is more flexible

c.  It allows better continuity of service as compared with the single bus

d.  It is more costly than that of the single bus system

Solution:

56.  Double-bus double breaker scheme has the following characteristics EXCEPT one, which one is this?

a.  Even with a circuit breaker failure, a station shutdown will not result.

b.  It reduces the likelihood of extended outages of any circuit due to circuit breaker trouble.

c.  It permits breaker maintenance without feeder outage.

d.  It gives more flexibility.

Solution:

57.  A large electric power distribution system is protected against surges and faults by

a.  protective gaps crossing drain cells

b.  high-speed relays detecting the trouble

c.  protective relays operating without a time delay

d.  radio communication system using flow frequency

Solution:

58.  Which of the following steps is used for isolating a circuit breaker for maintenance purposes?

a. pull the substation fuses

b. turn off the main generator

c. open the disconnect switches

d. ground the auxiliary contacts

Solution:

59.  In a generating and distribution system, current balance is provided by protective zones which are

a.  used to eliminate reflections on short transmission lines

b.  used to trip all circuit breakers in the system

c.  isolated during fault by disconnect switches

d.  monitored by differential relays

Solution:

60. For protection of parallel feeders fed from one end the relays required are:

a.  Non-directional relays at the source end and directional relays at the load end

b.  Non-directional relays at both the ends.

c.  Directional relays at the source end and non-directional at the load end.

d.  Directional relay at both the ends.

Solution:

61. If a fixed amount of power is to be transmitted over a certain length with fixed power loss, it can be said

a.  the volume of conductor required is inversely proportional to the square of voltage and that of the power factor of load

b.  the volume of the conductor is inversely proportional to voltage and that of power factor of load

c.  the volume of the conductor is proportional to square of the voltage and directly proportional to power factor of load

d.  the volume of the conductor required is proportional to voltage only

Solution:

62. Assuming the constant efficiency transmission, if the voltage is increased n times, the size of the conductor would be

a.  reduced to 1/n2 that of the original

b.  increased to n2 that of the original

c.  reduced to 1/n that of the original

d.  increased to n times that of the original

Solution:

63. In a distribution system, if the synchronous capacitors are to be used for improving the power factor, the correct location would be

a.  at the sending end

b.  at the receiving end

c.  in middle of the transmission line

d.  none of these

Solution:

64. In limiting case, the maximum cost of the phase advancing plant that would justify its installation is when its working cost is

a.  equal to the working cost of generating plant to give the same increase in power

b.  equal to working cost of the generating plant to give the less increase in power

c.  less than the working cost of generating plant to give the same increase in power

d.  greater than the working cost of the generating plant to give more increase in power

Solution:

65. The synchronizing power developed in the parallel operation of the alternators will be maximum when

a.  the armature have more reactances than their resistances

b.  the armature have less reactances than their resistances

c.  the armature reactances equal to their resistances

d.  the resistances of armatures are zero

Solution:

66. The actual division of the total kW load between alternators in power plant running in parallel depends upon the

c. a and b both

d. a or b

Solution:

67. Natural Uranium contains

a. 0.7% U235

b. 0.7% U235

c. 100% U235

d. 50% U235

Solution:

68. Which of the following will affect the transfer of the real power between the stations if they are interconnected?

b. In-phase voltage boost

c. Reactance

d. angular displacement between stations

Solution:

69. The size of the feeder is determined primarily by

a.  the current it is required to carry

b.  the percentage variation of voltage in the feeder

c.  the voltage across the feeder

d.  the distance over which the transmission is made

Solution:

70. If the voltage is increased n times, the current in the feeder is reduced to (for a given power delivered)

a. 1/n times of the original

b. 1/n2 times of the original

c. 1/√n times of the original

d.  √n times of the original

Solution:

71. In the d.c. three wire transmission system the cross-section of the neutral is generally

a. ¼ of the outer conductors

b. ½ of the outer conductors

c.  ⅓ of the outer conductors

d. equal to the outer conductors

Solution:

72. The Metal clad is related to

a. Amplidyne

b. Switchgear system

c. Synchros

d. Relays

Solution:

73. The power transmission capacity of the transmission line is

a.  proportional to the square of the operating voltage

b.  inversely proportional to the voltage

c.  proportional to the voltage

d.  inversely proportional to the square of the voltage

Solution:

74. Which of the following power plant has the maximum efficiency?

a. Thermal power plant

b. Hydro-electric power plant

c. Atomic Reactor

d. MHD

Solution:

75. The reactors used in most power station specially in HVDC is to limit the short circuit current in the alternators have very small resistance in comparison to reactance

a. because the high resistance will not help to limit the short circuit current

b.  to avoid the energy waste

c.  because the high resistance will raise the temperature and insulation of reactor will be spoiled

d.  to improve power factor

Solution:

76. The earthing transformer is used

a.  to avoid the harmonics in the transformers

b.  to provide artificial neutral earthing where the neutral points of the three phase system are not accessible

c.  to improve the current capacity of the neutral wire

d.  none of these

Solution:

77. To protect the power transformer (Y-Y, with neutral earthed) in power station against fault, the current transformer will have

a. Delta-delta connection

b. Delta-star connection

c. Star-delta connection

d. Star-star connection

Solution:

78. To protect the power transformer (Delta-delta) against fault, the current transformer will have

a. Delta-delta connection

b. Delta-star connection

c. Star-delta connection

d. Star-star connection

Solution:

79. Which of the following power system distribution gives the greater reliability?

a.  radial system of the distribution

b.  ring system of the distribution

c.  D.C. three wire system of the distribution

d.  A.C. three phase four wire system

Solution:

80. The diversity factor is defined as the

a.   Average demand over Maximum demand

b.  Sum of consumers maximum demand over Maximum load on the station

c.   Maximum demand over Sum of consumers maximum demand

d.   Average demand over Maximum load on the station

Solution:

81. The power intended to be available even under emergency condition is called

a. firm power

b. hot reserve

c. cold reserve

d. spinning reserve

Solution:

82. Which of the following generating stations has the minimum running cost?

a. Hydro-electric station

b. Nuclear power station

c. Thermal power station

d. Diesel power plant

Solution:

83. Overfluxing protection is recommended for

a.  generator transformer of the power plant

b.  auto-transformer of the power plant

c.  station transformer of the power plant

d.  Distribution transformer

Solution:

84. Which of the following statements is true if restricted earth fault protection is provided to star winding of the generator transformer

a.  one Ct in each phase and fourth in the neutral are provided and their secondaries are connected in parallel

b.  one CT is provided in the neutral

c.  two CTs are provided, one in R-phase and other Y phase with a CT in neutral

d.  in fact CTs are not required at all as the fault current is not very high

Solution:

85. Series capacitors are used to

a.  improve line voltage

b.  compensate line inductive reactance

c.  compensate line capacitive reactance

d. improve impedance

Solution:

86. High water level of a boiler drum can damage

a. boiler tubes

b. turbine and steam line

c. turbine only

d. none of these

Solution:

87. Which of the following statements is true?

a.  Shunt reactors are used for power factors improvement.

b.  Shunt reactors are used to control the line voltage.

c.  Shunt reactors are used to reduce the line impedance.

d.  Shunt reactors are used to eliminate line to ground capacitance.

Solution:

88. When a stator neutral of a generator is earthed through a distribution transformer, the stator earth fault is detected through

a.  an over-voltage relay connected across the secondary of the transformer

b.  an over-current relay connected across the secondary of the transformer

c.  an under-voltage relay connected across the secondary of the transformer

d.  none of these

Solution:

89. If high pressure heaters of steam cycle in power plant have high water level, what precaution shall be taken.

a.  trip the turbine

b.  trip the boiler

c.  trip the boiler feed pump

d.  bypass the heater from water side and close extraction value

Solution:

90. Which one of the following statements is not true?

a.  Fault levels in an all a. c system are less than in an a. c system with a D.C. link operating

b.  Large systems may be interconnected with d. c link of small capacity

c.  Limitation on the critical length of underground cables for use in A. C no longer exists if D.C transmission by cables is used.

d.  Corona loss and radio and TV interference with D.C. transmission is less

Solution:

91. Advantage of power system interconnection is

a.  Large size circuit breakers are required because of large short-circuit currents

b.  Machines of one system remain in step with machines of another system

c.  Fewer machines are required as reserve for operation at peak loads

d.  Optimization of machine can be done properly

Solution:

92. Economic studies have shown that D.C. transmission is cheaper than a. c transmission for lengths

a. below 300 km

b. beyond 600 km

c. beyond 1200 km

d. less than 100 mile

Solution:

93. Governors for controlling the speed of power generation units provide

a.  A flat speed -load characteristics

b.  An increase of speed with increasing load

c.  Speed is proportion with the load

d.  A decrease of speed with increasing load

Solution:

94. When two identical generating units are operated in parallel on governor control, and one machine has a 5% governor droop and the other a 10 % droop , the machine with the greater governor droop will

a.  Tend to take the greater portion of load changes

b.  Share load equally with the other machine

c.  Tend to take the larger portion of load changes.

d.  Tend to take the lesser portion of load changes.

Solution:

95. On load-frequency control installations, error signals are developed proportional to the frequency error. If frequency declines , the error signal will act to

a.  Increase prime move input to the generators

b.  Reduce prime mover input to the generators

c.  Increase generator voltages

d.  Increase impedance of the line

Solution:

96. When inter-connected power systems operate with tie-line bias, they will respond to

a.  Frequency changes only

b.  Both frequency & tie -line load changes

d. Drooping voltage

Solution:

97. When generating units in a power plant are loaded with equal incremental costs, the cost of generation is

a. maximum

b. minimum

c. not affected

d. zero

Solution:

98. Incremental heat – rate curves for thermal generating units are used to determine the

a.  fuel cost in P/hour

b.  values to which the units should be loaded to decrease the fuel costs to a minimum

c.  Optimal cost

d.  none of these.

Solution:

99. In economic operation of a power system , the effect of increased penalty factor between a generating plant and system load centre is

a.  to decrease the load on the generating plant

b.  to increase the load on the plant

c.  to hold the plant load constant.

d.  To maintain power factor of the plant

Solution:

100. Non-conventional source-based power plants are generally best suited for

a.  Working with the nearby power grid

b.  Isolated operation from the power grid

c.  Operation with similar plants irrespective of length of connecting transmission system

d. Island

Solution:

P inoyBIX educates thousands of reviewers and students a day in preparation for their board examinations. Also provides professionals with materials for their lectures and practice exams. Help me go forward with the same spirit.

“Will you subscribe today via YOUTUBE?”

Subscribe

PinoyBIX Engineering. © 2014-2020 All Rights Reserved | How to Donate? |  