Power Plant Engineering Objective Questions And Answers

101. In a moderate size steam power station, electrical power is generated at

(a) 440 V
(b) 1.1 kV
(c) 11 kV
(d) 33 kV

102. If two synchronous generators are connected, loss of synchronism will result in

(a) stalling of generators.
(b) wild fluctuations in current.
(c) wild fluctuations in current and voltage.
(d) none of the above.

103. A large synchronous generator is feeding power into an infinite bus at slightly lagging power factor. If a total loss of field occurs and the system can supply sufficient reactive power without a large terminal voltage drop, the unit will

(a) continue to run as a synchronous generator and no tripping is necessary.
(b) get short-circuited and it should be tripped instantaneously.
(c) run as an induction generator and it should be tripped after a time delay.
(d) run as a synchronous motor and it should be tripped after a time delay.

104. Unit of regulation of speed governor is

(a) Hz/MW
(b) MW/Hz
(c) Unit less
(d) km/sec

105. Three identical generators supply power in a system having lossless transmission lines. Generator 1 is equipped with a speed governor that maintains its speed constant at the rated value while generators 2 and 3 have governors with droops of 5% and 4% respectively. For a given increase in system load in the steady state

(a) Generators 1, 2, 3 will share the increased load in the ratio of 0 : 5 : 4.
(b) Generators 1, 2, 3 will share the increased load equally.
(c) Generators 1, 2, 3 will share the increased load in the ratio of 0 : 4 : 5.
(d) Generator 1 will alone take the entire increased load and the output of generators 2 and will remain unchanged.

106. For stable operation of interconnected system, the passive element that can be used as the interconnecting element is

(a) reactor.
(b) resistor.
(c) capacitor.
(d) resistor and capacitor.

107. To meet the reactive power requirements at load centers usually

(a) shunt capacitors are used.
(b) series capacitors are used.
(c) tap changing transformers are used.
(d) shunt reactors are used.

108. A power system needs injection of VARs at

(a) off-peak load.
(b) peak load.
(c) both peak and off-peak load.
(d) full load.

109. The injection of VARs is required to

(a) compensate for line losses.
(b) get a good voltage profile.
(c) increase the voltage at the receiving end.
(d) all of the above.

110. Shunt capacitors in a substation

(a) consume lagging VARs.
(b) deliver lagging VARs.
(c) consume active power.
(d) deliver active power.

111. The principle of incremental costs is employed for deciding the

(a) sequence of adding units.
(b) load allocation between units in operation.
(c) total plant capacity to be operated.
(d) all of the above.

112. For a thermal power plant the input output characteristic is given by Q = 8 + P + 0.08 P² where Q and P are heat input and power output, respectively in MW. The maximum thermal efficiency would be

(a) 26.5%
(b) 30.5%
(c) 34.5%
(d) 38.5%

113. For economy measure the generators at a power plant operate at

(a) equal loads.
(b) load proportional to the ratings.
(c) equal incremental cost.

114. Two generating plants feed a load centre through a transmission network. For maximum economy

(a) the incremental cost of power supplied at the load centre should be the same fur both the plants.
(b) the incremental fuel cost should be the same for both the plants.
(c) the more efficient plant should share more load.
(d) none of the above.

115. In the optimum generator scheduling different power plants, the minimum fuel cost is obtained when

(a) only the incremental fuel cost of each plant is the same.
(b) the penalty factor of each plant is the same.
(c) the ratio of the incremental fuel cost to the penalty factor of each plant is the same.
(d) the incremental fuel cost of each plant multiplied by its penalty factor is the same.

116. If the generating station is situated very close to the load centre, the penalty factor for this unit is

(a) zero.
(b) almost unity.
(c) negative.
(d) very high.

 

• Power Plant Engineering MCQ Part – 1
• Power Plant Engineering MCQ Part – 2
• Power Plant Engineering MCQ Part – 3
• Power Plant Engineering MCQ Part – 4
• Power Plant Engineering MCQ Part – 5

©yourelectricalguide.com/ power plant engineering objective questions and answers.