POWER SYSTEM ,,TRANSMISSION
Q 1 Transmission of power by ac cables is impossible beyond
a. 35 – 45 km
b. 500 km
c. 300 km
d. 10 – 15 km
Answer
ANSWER: 35 – 45 km
Q 2 Transmission efficiency of a transmission line increases with the ____.
a. decrease in power factor and voltage.
b. increase in power factor and voltage.
c. increase in power factor but decrease in voltage.
d. increase in voltage and decrease in power factor.
Answer
ANSWER: increase in power factor and voltage
Q 3 The value of A parameter of a transmission line
a. Increases with increase in length of line
b. Decreases with increase in line length
c. Is independent of line length
d. None of these
Answer
ANSWER: Increases with increase in length of line
Q4 What is the normal range of angle for the parameter A?
a. 90 °
b. 70 ° - 40 °
c. 40 ° - 10 °
d. 0 - 10 °
Answer
ANSWER: 0 - 10 °
Q5 What happens in a long transmission lines under no load?
a. The receiving end voltage is less than the sending end voltage.
b. The sending end voltage is less then receiving end voltage.
c. The sending end voltage is equal to receiving end voltage.
d. None of these
Answer
ANSWER: The sending end voltage is less then receiving end voltage.
Q6 In the nominal p method which among these are divided into two halves?
a. Series impedance
b. Shunt capacitance
c. Both (A) and (B)
d. None of these
Answer
ANSWER: Shunt capacitance
Q7 A line of what length can be classified as a medium transmission line?
a. 90 – 100 km
b. 50 – 150 km
c. 150 – 200 km
d. Above 200 km
Answer
ANSWER: 50 – 150 km
Q8 What is the power factor angle of the load for maximum voltage regulation?
a. tan-1 (X/R)
b. cos-1 (X/R)
c. tan-1 (R/X)
d. cos-1 (R/X)
Answer
ANSWER: tan-1 (X/R)
Q9 A condenser condenses the steam coming out from_____.
a. Boiler
b. Turbine
c. Economiser
d. Super heater
Answer
ANSWER: Turbine
Q10 Water used in the steam plant is used for cooling in_______.
a. Condenser
b. Turbine only
c. Boiler tube
d. Boiler tubes and turbines
Answer
ANSWER: Condenser
Q11 Air- preheater in a steam power plant_____.
a. Recovers the heat from the flue gases leaving the economiser.
b. Improves combustion rate.
c. Raises the temperature of the furnace gases.
d. All of these.
Answer
ANSWER: All of these.
Q12 The governing principle of steam turbines are ______.
a. Nozzle control governing
b. Throttle governing
c. Bypass governing
d. All of these
Answer
ANSWER: All of these
Q13 ) Turbo alternators run at speeds
a. Constant speed of 3000 rpm.
b. Constant speed of 1000 rpm.
c. A variable speed of above 1000 rpm.
d. None of the above
Answer
ANSWER: A variable speed of above 1000 rpm.
Q14 The reheat factor in a steam turbine depends on
a. Stage efficiency.
b. Initial pressure and temperature.
c. Exit pressure.
d. All of the above.
Answer
ANSWER: All of the above.
Q15 The use of air preheater increase the temp of the air by about______.
a. 50°
b. 20°
c. 5°
d. 30°
Answer
ANSWER: 20°
Q 16 The draught produced by the chimney is______.
a. Forced draught
b. Natural draught
c. Induced draught
d. Balanced draught
Answer Explanation Related Ques
ANSWER: Natural draught
Q17 The pipes carrying the steam are made of ___.
a. Steel
b. Cast iron
c. Aluminium
d. Cobalt
Answer
ANSWER: Steel
Q18 The thermal efficiency of a steam plant is defined as?
a. The ratio of heat equivalent of electrical output to the heat of combustion of
coal.
b. The ratio of heat of combustion of coal to the heat equivalent of electrical
output.
c. The ratio of heat equivalent of mechanical energy transmitted to the turbine shaft
to the (heat of combustion of coal...
d. The ratio of heat of combustion of coal to the heat equivalent of mechanical
energy transmitted to the turbine shaft.
Q19 The thermal efficiency of a steam power station is.......
A.38%
B.28%..
C.40%
D.45%
Q20 Rankine cycle efficiency in a good steam power station may be in the range between........
A.15% - 20%
B.35% - 40%...
C.50% - 60%
D.90% - 95%
Q21 A steam power station requires space........
A.Equal to diesel power station
B.less than diesel power station
C.More than diesel power station
D.None of the above
Q22 The height of chimney in a steam power plant is governed by........
A.Flue gases quantity
B.The draught to be produced
C.Control of pollution
D.Corner of power plant
Q23 The major heat loss in a steam power station occurs in ........
A.Heat chamber
B.Penstock
C.Spillways
D.Condenser
Q24 The cost of fuel transportation is maxmimun in........
A.Hydro-electric power plant
B.Steam power plant..
C.Nuclear power plant
D.None of these
Q25 Standby loss is maximum in........
A.Nuclear power plant
B.Hydro-electric power plant
C.Thermal power plant..
D.Diesel power plant
Q26 The modern steam turbines are
(A) Impulse turbines
(B) Reaction turbines
(C) Impulse-reaction turbines..
(D) None of the above
Q27 Economisers improve boiler efficiency by
(A) 1 to 5 %
(B) 4 to 10 %..
(C) 10 to 12 %
(D) None of these
Q28 In coal preparation plant, magnetic separators are used to remove (A) Dust
(B) Clinkers
(C) Iron particles
(D) Sand
Q29 Load center in a power station is
(A) Center of coal fields
(B) Center of maximum load of equipments
(C) Center of gravity of electrical system
(D) None of the above
Q30 Steam pressure in a steam power station, which is usually kept nowadays is of the order of
(A) 20 kgf/cm2
(B) 50 kgf/cm2
(C) 100 kgf/cm2
(D) 150 kgf/cm2..
Q32 Economizer is used to heat
(A) Air
(B) Feed water
(C) Flue gases
(D) All above
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