Exam 3 September 2018, questions and answers PDF

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Re Refr fr fres es esher her 2018 1. Thin homogenous metallic air containing hole is heated sufficiently to cause expansion, if the coefficient of surface expansion is linear, the area of the hole will Increase at the same rate as the area of the metal increases 2. Ice is slippery when a man walks on it because Increase of pressure causes it to melt 3.

Which statement is true for a fluid? It cannot sustain a shear force at rest

4. How are lines of constant pressure in a fluid related to the force field? They are perpendicular to the force field 5. The continuity equation is applicable to Conservation of mass 6. Which of the following describes shear stress in moving fluid? A. It is proportional to the absolute viscosity B. It is proportional to the velocity gradient at the point of interest C. Both A and B 7. What are the units of Reynolds number for pipe flow None of the above 8. A Kaplan turbine is A low head axial flow turbine 9. What is the absolute of a real fluid at the surface? The velocity of the surface 10. Two major types of chemical bonds are observed in chemical bonding, ionic and covalent. Which of the following is a bond that is least ionic in character H2 11. A substance is oxidized when which of the following occurs? It loses electrons 12. Which of the following oxidizing and reducing agents in the following reaction? 2CCI4 + K2CrO4 —> 2CI2CO + CrO2CI2 + 2KCI There are no oxidizing or reducing agents in this reaction 13. For stable equilibrium of floating body, its metacenter should lie Above the center of gravity 14. The maximum continuous power available from a hydroelectric plant under the most adverse hydraulic conditions is called

Firm power 15. Reactions generally proceed faster at higher temperatures because of which of the following A. The activation energy is less B. The molecules collide more frequently Both A and B 16. The thermodynamic cycle used in a thermal powerplant is Rankine 17. Isentropic flow is defined as Reversible adiabatic flow 18. It is impossible to construct a heat engine that operates in cycle and receives a given quantity of heat from a high temperature body and thus equal amount of work. This implies that it is impossible to construct a heat engine that has 100% thermal efficiency. The above statement is known as Kelvin-Plank’s Law 19. Which of the following thermodynamic relations are incorrect? H = U - pV 20. Which of the following is true for water at a temperature where enthalpy is zero? Internal energy is negative. 21. Which of the following describes a streamline? I. It is a mathematical concept II. It cannot be cross by the flow I and II 22. Under what conditions is mass conserved in fluid flow? It is always conserved 23. Which of the following is not true regarding the Blasius boundary layer solution? It is valid only for potential flow. 24. Which of the following properties are intensive properties? I. Temperature

II. Pressure

III. Composition

I, II, and III 25. For an ideal turbojet, all the following statements are true except? The work produced by the turbine is greater than the work required by the compressor 26. In a combustion chamber, fuel is burned to raise the temperature of the medium prior to production of work throughout expansion process. The heat generated during the combustion reaction is the Heat of reaction 27. Which of the following characteristics of the alkaline earth elements is unique to this group of elements?

They are in group IIa of the periodic table 28. Metals are conductive because The electrons are loosely bound to the nuclei and therefore mobile 29. Which of the following leads to a reduction in the electrical resistivity of a pure metal? Annealing 30. At absolute zero temperature (0K), all the valence electrons in an intrinsic semiconductor are in The valence bond 31. As a simplex algorithm progresses from one solution to the next in a linear programming maximization problem. What will happen to the value of the objective function? It will decrease or stay the same 32. In the design of a reinforced concrete structure, tensile strength of the concrete is normally Neglected 33. Which one refers to technological merger? Digital convergence 34. A technician installs a new video card but it shows upon boot on the system VGA display. What is the possible reason? Video card not compatible 35. The energy efficiency ratio EER of a refrigerator or air conditioner is the ratio between The heat in BTU extracted per hour and the power in Watts the machine uses 36. Ton of refrigeration is a unit equivalent to 12660 kN-m/Hr 37. The coordination number of body-centered cubic BCC structure is 8 38. Why is the following expression unacceptable as a FORTRAN integer constant 237,120 It contains a comma 39. Which of the following is a FORTRAN expression corresponding to ln (8 + sqr.root b^3 ) / sin( c^2 + 1)? Log^-1 (8 + sqr.root b^3 ) / sin(c^2 +1) 40. Legally required standby systems are typically installed to serve loads such as? I. Sewerage disposal

II. Data processing

III. Refrigeration system

I and III only 41. What is the default view when printing a document? Portrait

42. _¬¬¬______ is a software that allows users to have fast and flexible access to information in large documents, constructing associations among data items needed Hypertext 43. XYZ corporation manufacture book cases that sells to P65 each. It costs XYZ 35000 per year to operate its plant. The sum includes rent depreciation charges on equipment and salary payments. If the additional cost to produce one bookcase is P50, how many cases must be sold each year for XYZ to avoid taking a loss? 2334 cases 44. What is the borrower of a particular loan almost always required to do during repayment. Repay the loan over an agreed-upon amount on time 45. How is material usage variance defined ( Quantity issued – Standard quantity) ( Standard price) 46. How is material purchased price variance defined ( Quantity Purchased x Actual Price¬) – (Quantity Purchased x Standard Price) 47. A single electrode consisting of a _______ which does not have a resistance to ground of 25 ohms or less shall be augmented by one additional electrode. I. Rod

II. Pipe

III. Plate

I, II or III 48. A complete environmentally protected unit consisting of solar cells _____ designed to generate AC power when exposed to sunlight A. Inverter

B. Optics

C. Exclusive of tracker

All of the above 49. It is defined as the quality of voltage including its frequency and resulting current that are measured in the distribution system during normal conditions. Power Quality 50. What does acronym EPIRA mean? Electric Power Industry Reform Act 51. If the shunt admittance of the transmission line is ignored, the torque angle at which maximum power will occur is π/2 52. If Vs = Vr = 33 kV three phase and x = 13ohm/phase, what will be the maximum power transmission per phase 28 MW 53. The power transmission capacity of the transmission line is proportional to the Square of the voltage 54. A transformer has a reactance of 0.04 per unit, if the secondary of the transformer is short-circuited

with nominal voltage applied to the primary, a symmetrical short-circuit current will be 25 times of the full load current 55. The Buchholz relay is used to protect Oil-immersed transformers against all internal faults

56. The effect of electrical shock on the human body will depend on Current flowing in the body 57. The Class C insulation can withstand 180 degrees Celsius 58. Which of the following distribution system gives a greater reliability? Wind system 59. The effect of series capacitor on a transmission line is To improve the steady-state stability 60. Two transmission lines of the surge impedance of 600 ohms, each is linked by a cable, what should be the surge impedance of the cable if there were no reflection at the junction? 600 ohms 61. Series capacitor are used to Compensate for the line inductive reactance 62. Split phase relaying responds to faults between turns of a transformer True 63. For a detection of the occurrence of the severe synchronizing power surges Mho relays are best suited 64. The power loss is important for the design of Transmission line 65. Which of the following parameter can be neglected for a short transmission line Capacitance 66. If the height of a transmission tower is decreased The capacitance of the line will increase 67. If the capacitance of the transmission line is increased The transmitted power will increase 68. Which of the following method may be used to inject reactive power in the transmission line Shunt capacitor 69. Which of the following insulator will be selected for high voltage application

Suspension type 70. The disadvantages of transmission line as compared to cable system are Atmospheric hazards like smoke, ice, exposures to lightning, interference of telecommunication circuits, etc. 71. The load must not be connected directly on Transmission line 72. The safe working life of the underground cable is taken as 40 years 73. Generally, the porcelain insulators are glazed because It prevents the absorbing tendency of gases and water vapors 74. Name the effect which resulted because of the size of conductor, frequency and the specific resistance of the conducting material Skin effect 75. The capacitor bank is installed To improve the power factor and voltage magnitude 76. A circuit breaker serves the purpose of A. Switching on and switching off under normal working conditions B. Protecting the circuit under abnormal condition of load C. Protecting the circuit under faulty conditions All of the above 77. Peak load plants are designed to supply power at Low capital cost and high operating cost 78. As compared to steam stations hydropower station have A. More cost of installation B. Less maintenance and fuel cost Both A and B 79. The peak load demand of an industrial area is met by Diesel power plant 80. Factors involved in fixing tariff are A. Secured return from each consumer B. Simplicity cheapness and easy explainability, C. Incentives to consumer and charge according to use All of these 81. Diversity factor is the

A. Ratio of maximum load on the station to sum of consumers maximum demands B. Ratio of maximum demand to average demand Reciprocal of A 82. The surge impedance of transmission line differs from its characteristics impedance as surge impedance consider line resistance of Finite value 83. Booster transformers are used to increase the voltage at ________ of a transmission line Intermediate points 84. Long transmission line has a surge impedance of approximately 400 ohms 85. The transfer of real power between interconnected stations is affected by Capacitance 86. Voltage gradient in a conductor is highest at its Surface 87. The real part of propagation constant of a transmission line is Attenuation constant 88. The sag of the transmission line is affected by A. Its own weight and weight of the ice B. Temperature and wind condition Both A and B 89. When horizontal tension H increases by 20%, the tension T changes by Increase of 20% 90. An ACSR conductor has layers around its single center strands. The total number of strands will be 3n^2 – 3n + 1 91. When the conductor of a 3-phase circuit are not spaced equilaterally, the transportation is done to Balance the 3 phases of the circuit 92. The transmission line inductance contributed by The current in the other conductor 93. The ratio of capacitance of line to neutral and line to line capacitance of a transmission line having 2 conductors is 2.0 94. The presence of earth alters the A. Electric field of the line

B. Capacitance of the line Both A and B 95. In both skin effect and proximity effect A. Effective internal reactance of the conductor gets decrease B. Their effect depends upon conductor size, the frequency, resistivity and permeability C. The effect is negligible at all frequency All of these 96. The skin effect in conductors is due to non-uniform distribution of current in it and major portion of the current is near the ________ of the conductor Surface 97. For a short transmission line A. Vr = Vs – Isz B. A = B = 1 C. 0 and B=Z All of these 98. Ferranti effect states that the receiving end voltage on no load is More than that at the sending end 99. Advantages of constant voltage transmission are A. Improve power factor at heavy load B. Same voltage is maintained at load C. All loads increase power transmission over long distance All of the above 100.

The characteristics impedance of a loss-less overhead line has a value of

400- 600 ohms...