Economics of Power Generation PART 3 ONLINE EE Multiple Choice Questions

Economics of Power Generation PART 3

31. A steam power station will run with maximum efficiency when it is run
(A) at low steam pressures
(B) on pulverized coal
(C) at higher speeds
(D) near full load.Get Answer

32. Which of the following is likely to result in lower efficiency of a power station ?
(A) Varying loads
(B) Low voltage generation
(C) Low turbine speeds
(D) Non-automatic controls.

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Questions 33 to 36 refer to the following information.

The following factors are associated with power plant operation
I. High efficiency
II. High availability
III. Quick starting
IV. Low capital cost.

Economics of Power Generation PART 3

33. Which factor is least important for base load plants ?
(A) I
(B) II
(C) III
(D) IV.

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34. Which two factors are of significant requirement for base load plant ?
(A) I and II only
(B) III and IV only
(C) II and III only
(D) I and IV only.

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35. Which two factors are of importance for peak load plant ?
(A) I and III only
(B) II and III only
(C) I and IV only
(D) III and IV only.

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Economics of Power Generation PART 3

36. Which factors are favorable to a diesel power plant as compared to a steam power plant ?
(A) I and III only
(B) I, II and III B only
(C) II, III and IV only
(D) I, II. Ill and IV.

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37. In a 440 V system, in order to obtain the minimum cost and maximum benefits, the capacitor should be
installed
(A) at the load
(B) near the transformer
(C) any where in the circuit
(D) near the earthling point.

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38. In case of medium sized induction motor, the power factor will be maximum at
(A) No load
(B) 50% load
(C) Full load
(D) Power factor remains constant at all loads.

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39. A coaxial line is filled with a dielectric of relative permitivity 9. If C denotes the velocity of propagation in free space, the velocity of propagation in the line will be
(A) 3 C
(B) C
(C) C / 3
(D) C / 9.

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Economics of Power Generation PART 3

40. A direct voltage is applied to a peak diode voltmeter in which scale is calibrated to read rms voltage of a sine wave. If the meter reading is 36 V rms, the value of the applied direct voltage is
(A) 25 V
(B) 36 V
(C) 51 V
(D) 72 V.

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41. A power station has annual load factor of 50% and capacity factor of 40%. If the maximum demand is 15 MW, the reserve capacity of the plant is
(A) 1250 kw
(B) 2500 kw
(C) 3750 kw
(D) 4750 kw.

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42. Which of the following will not contribute to low power-factor ?
(A) Partially loaded induction motors
(B) Replacement of fluorescent lamps with incandescent lamps
(C) Use of rectifiers instead of synchronous motor-generator sets for dc power supply
(D) Increased installation of electronic equipments, air- conditioning units, etc.

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Economics of Power Generation PART 3

43. Which of the following may not be the effect of low plant operating power factor ?
(A) Over loaded transformers
(B) Reduced voltage level
(C) Improved illumination from lighting
(D) Over loaded cables.

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44. Identify the incorrect relation
(A) power factor = KW / kVA
(B) kW = kVA x power factor
(C) kVA x kW = power factor
(D) kVA = kW / power factor.

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45. The power factor of a system on a 460 V, 3 phase, 60 Hz, in which the ammeter indicates 100 amp and the watt meter reads 62 kW will be
(A) 0.95
(B) 0.78
(C) 0.65
(D) 0.55.

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Economics of Power Generation PART 3