Railways NTPC (Technical Ability) Turbomachinery Question Bank

done Turbomachinery Total Questions - 120

• question_answer1)
  Optimum pressure ratio for maximum specific output for ideal gas turbine plant operating at initial temperature of 300 K and maximum temperature of 1000 K is closer to:
  A)
  4                                  done clear
  B)
  8 done clear
  C)
  12                                 done clear
  D)
  16 done clear
  View Solution play_arrow

• question_answer2)
  In a parallel flow gas turbine recuperator, the maximum effectiveness is:
  A)
  100%                            done clear
  B)
  75% done clear
  C)
  50%                  done clear
  D)
  between 25% and 45% done clear
  View Solution play_arrow

• question_answer3)
  When the outlet angle from the rotor of a centrifugal compressor is more than \[90{}^\circ ,\] then the blades are said to be:
  A)
  Forward curved done clear
  B)
  Backward curved done clear
  C)
  Radial                                   done clear
  D)
  Either backward or forward curved. done clear
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• question_answer4)
  According to fan laws, which of the following relation is valid? (Q \[-\] discharge, N \[-\] speed, D \[-\] diameter) Subscripts 1 and 2 for two sets of conditions):
  A)
  \[\left( \frac{{{Q}_{1}}}{{{Q}_{2}}} \right)={{\left( \frac{{{N}_{1}}}{{{N}_{2}}} \right)}^{2}}\]         done clear
  B)
  \[\left( \frac{{{Q}_{1}}}{{{Q}_{2}}} \right)={{\left( \frac{{{N}_{1}}}{{{N}_{2}}} \right)}^{3}}\] done clear
  C)
  \[\left( \frac{{{Q}_{1}}}{{{Q}_{2}}} \right)={{\left( \frac{{{D}_{1}}}{{{D}_{2}}} \right)}^{2}}\]         done clear
  D)
  \[\left( \frac{{{Q}_{1}}}{{{Q}_{2}}} \right)={{\left( \frac{{{D}_{1}}}{{{D}_{2}}} \right)}^{3}}\] done clear
  View Solution play_arrow

• question_answer5)
  The Mach number at inlet of gas turbine diffuser is 0.3. The shape of the diffuser would be:
  A)
  Converging                     done clear
  B)
  diverging I done clear
  C)
  Stagnation enthalpy done clear
  D)
  stagnation pressure done clear
  View Solution play_arrow

• question_answer6)
  For two-stage compressor in which index of compression for low pressure stage is m and for high pressure stage is n. The load sharing with perfect intercooling is expressed as:
  A)
  \[\frac{{{W}_{1}}}{{{W}_{2}}}=\frac{m(n-1)}{n(m-1)}\]          done clear
  B)
  \[\frac{{{W}_{1}}}{{{W}_{2}}}=\frac{n(n-1)}{m(m-1)}\] done clear
  C)
  \[\frac{{{W}_{1}}}{{{W}_{2}}}=\frac{n}{m}\]                        done clear
  D)
  \[\frac{{{W}_{1}}}{{{W}_{2}}}=\frac{m}{n}\] done clear
  View Solution play_arrow

• question_answer7)
  The degree of reaction of a turbo machine is defined as the ratio of the:
  A)
  Static pressure change in the rotor to that in the stator done clear
  B)
  Static pressure change in the rotor to that is the stage. done clear
  C)
  Static pressure change in the stator to that is the rotor. done clear
  D)
  Total pressure change in the rotor to that in the stage. done clear
  View Solution play_arrow

• question_answer8)
  Consider the following statements:

  1. Reciprocating compressors are best suited for high pressure and low volume

  2. The effect of clearance volume on power consumption is negligible for the same volume of discharge.

  3. While the compressor is idling, the delivery valve is kept open by the control

  4.  Intercooling of air between the stages of compression helps to minimize losses.

  Of these statements:
  A)
  1 and 2 are correct   done clear
  B)
  1 and 3 are correct done clear
  C)
  2 and 4 are correct done clear
  D)
  3 alone is correct done clear
  View Solution play_arrow

• question_answer9)
  Consider the following statements:

  The typical air velocities in the ducts of air- conditioning systems are:

  1. Lower in residential buildings as compared to those of public buildings

  2. higher in residential buildings as compared to those of public buildings

  3. Higher in industrial buildings has compared to those of public buildings

  4. Equal in all types of buildings

  Which of these statements is/are correct?
  A)
  1 alone              done clear
  B)
  1 and 3 done clear
  C)
  2 and 3             done clear
  D)
  4 alone done clear
  View Solution play_arrow

• question_answer10)
  A multistage compressor is to be designed for a given flow rate pressure ratio. If the compressor consists of axial flow stages followed by centrifugal instead of only axial flow-stages, then the:
  A)
  Overall diameter would be decreased done clear
  B)
  Overall diameter would be increased done clear
  C)
  Axial length of the compressor would be increased done clear
  D)
  Axial length of the compressor would be decreased. done clear
  View Solution play_arrow

• question_answer11)
  The clearance volume of a reciprocating compressor directly affects:
  A)
  Piston speed done clear
  B)
  Noise level done clear
  C)
  Volumetric efficiency done clear
  D)
  Temperature of air after compression. done clear
  View Solution play_arrow

• question_answer12)
  In an axial flow gas turbine, the hot gases approach the rotor inlet with an absolute velocity of 600 m/s in a direction \[30{}^\circ \] from the wheel tangent. The gases leave the rotor axially. If the blade speed is 300 m/s, then the theoretical power output per kg/s of gas flow will be approximately:
  A)
  132 kW             done clear
  B)
  156 kW done clear
  C)
  172 kW             done clear
  D)
  205 kW. done clear
  View Solution play_arrow

• question_answer13)
  The difference between the comfort air-conditioning and industrial air-conditioning lies in the:
  A)
  Equipment used  done clear
  B)
  process adopted done clear
  C)
  Indoor requirements         done clear
  D)
  ambient conditions done clear
  View Solution play_arrow

• question_answer14)
  The state of air supplied by a cooling coil with a by-pass factor 'X' lies on the psychrometric chart at the:
  A)
  Intersection of RSHF line with saturation curve done clear
  B)
  Intersection of GSHF line with saturation curve done clear
  C)
  Point which divides RSHF line in proportion to 'X' and \[(1-x)\] done clear
  D)
  Point which divides ESHF line in proportion to 'X 'and \[(1-x)\] done clear
  View Solution play_arrow

• question_answer15)
  Performance of a reciprocating Compressor is expressed by:
  A)
  \[\frac{Isothermal\,\,work}{Indicated\,\,work}\]       done clear
  B)
  \[\frac{Indicated\,\,work}{Isothermal\,\,work}\] done clear
  C)
  \[\frac{Adiabatic\,\,work}{Indicated\,\,work}\]        done clear
  D)
  \[\frac{Indicated\,\,work}{Adiabatic\,\,work}\] done clear
  View Solution play_arrow

• question_answer16)
  In a simple gas turbine power plant operating on standard Brayton cycle power needed to drive the compressor is 175 kW, rate of heat supplied during constant pressure heat addition process is 675 kW. Turbine output obtained during expansion is 425 kW. What is the rate of heat rejection during constant pressure heat rejection?
  A)
  75 kW               done clear
  B)
  425 kW done clear
  C)
  500 kW             done clear
  D)
  925 kW done clear
  View Solution play_arrow

• question_answer17)
  Which one of the following is the correct statement?
  A)
  Both work ratio and thermal efficiency improve. done clear
  B)
  Work ratio improves but thermal efficiency decreases. done clear
  C)
  Thermal efficiency improves but work ratio decreases. done clear
  D)
  Both work ratio and thermal efficiency decrease. done clear
  View Solution play_arrow

• question_answer18)
  A gas turbine cycle with infinitely large number of stages during compression and expansion leads to which one of the following?             
  A)
  Stirling cycle                   done clear
  B)
  Atkinson cycle done clear
  C)
  Ericsson cycle     done clear
  D)
  Brayton cycle done clear
  View Solution play_arrow

• question_answer19)
  Pulse jet engine operation can be idealized/approximated to follow which one of the following?
  A)
  Brayton cycle     done clear
  B)
  Ericsson cycle done clear
  C)
  Lenoir cycle                   done clear
  D)
  Stirling cycle done clear
  View Solution play_arrow

• question_answer20)
  Consider the following statements:

  For a single-stage water cooled air compressor,

  1.  The volumetric efficiency decreases as the pressure ratio is increased.

  2.  Shaft power/\[{{m}^{3}}\]/min of free air increases as the pressure ratio is increased.

  Which of the statements given above is/are correct?
  A)
  1 only               done clear
  B)
  2 only done clear
  C)
  Both 1 and 2                  done clear
  D)
  neither 1 nor 2 done clear
  View Solution play_arrow

• question_answer21)
  In aircraft gas turbines, the axial flow compressor is preferred because:
  A)
  Of high pressure rise        done clear
  B)
  It is stall free done clear
  C)
  Of low frontal area          done clear
  D)
  Of higher thrust done clear
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• question_answer22)
  In axial flow compressor, exit flow angle deviation from the blade angle is a function of:
  A)
  Blade camber done clear
  B)
  space-chord ratio done clear
  C)
  Both blade camber and space-chord ratio        done clear
  D)
  Blade camber and incidence angle  done clear
  View Solution play_arrow

• question_answer23)
              The thrust of a jet propulsion power unit can be increased by:                                   
  A)
  Injecting water into compressor                done clear
  B)
  Burning fuel after gas turbine                  done clear
  C)
  Injecting ammonia into the combustion chamber                              done clear
  D)
  all of the above,          done clear
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• question_answer24)
                       In a gas turbine cycle with two stages of rehearing.  working between maximum pressure \[{{p}_{1}}\] and minimum  pressure \[{{p}_{4}},\] the optimum reheat pressure would be:
  A)
  \[{{({{p}_{1}}{{p}_{4}})}^{1/3}}\] and \[{{({{p}_{1}}{{p}_{2}})}^{2/3}}\] done clear
  B)
  \[{{(p_{1}^{2}{{p}_{4}})}^{2/3}}\] and \[{{({{p}_{1}}p_{4}^{2})}^{1/2}}\] done clear
  C)
  \[\sqrt{{{p}_{1}}{{p}_{4}}}\] and \[{{p}_{1}}\sqrt{{{p}_{4}}}\] done clear
  D)
  \[{{({{p}_{1}}{{p}_{4}})}^{1/2}}\] and \[{{({{p}_{1}}{{p}_{4}})}^{2/3}}\] done clear
  View Solution play_arrow

• question_answer25)
  Intercooling in gas turbines:                  
  A)
  Decreases net output but increases thermal efficiency                                     done clear
  B)
  Increases net output but decreases thermal efficiency                         done clear
  C)
  Decreases both net output and thermal efficiency                        done clear
  D)
  Increases both net output and thermal efficiency done clear
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• question_answer26)
  For a two-stage reciprocating compressor, compression from pressure \[{{p}_{1}}\] to \[{{p}_{3}}\] is with perfect intercooling and no pressure losses. If compression in both cylinders follows the same polytropic process and the atmospheric pressure is \[{{p}_{a'}}\] then the intermediate pressure \[{{p}_{2}}\] is given by:                     
  A)
  \[{{p}_{2}}=({{p}_{1}}+{{p}_{3}})/2\]           done clear
  B)
  \[{{p}_{2}}=\sqrt{{{p}_{1}}.{{p}_{3}}}\] done clear
  C)
  \[{{p}_{2}}={{p}_{a}}\frac{{{p}_{3}}}{{{p}_{1}}}\]             done clear
  D)
  \[{{p}_{2}}={{p}_{a}}.\sqrt{{{{p}_{3}}}/{{{p}_{1}}}\;}\] done clear
  View Solution play_arrow

• question_answer27)
  If (to geometrically similar impellers of a centrifugal compressor are operated at the. same speed, then their head discharge and power will vary with their diameter ratio:                             
  A)
  \[d,{{d}^{2}}\,\,and\,\,{{d}^{3}}\]Respectively                  done clear
  B)
  \[d,\,{{d}^{3}}\,\,and\,\,{{d}^{5}}\] Respectively                  done clear
  C)
  \[d,\,{{d}^{3}}\,\,and\,\,{{d}^{5}}\] Respectively                done clear
  D)
  \[{{d}^{2}},d\,\,and\,\,{{d}^{3}}\] Respectively    done clear
  View Solution play_arrow

• question_answer28)
                High positive incidence in an axial compressor blade raw leads to:
  A)
  Suppression of separation of flow on the blade done clear
  B)
  Choking of the flow done clear
  C)
  Separation of flow on the pressure side of the blade done clear
  D)
  Separation of flow on the suction side of the blade. done clear
  View Solution play_arrow

• question_answer29)
  Consider the following statements about modification? gas turbine power plant working en a simple Brayton cycle:

  1. Incorporation of regeneration process increases specific work output as well as thermal efficiency.

  2. Incorporation of regeneration process increases thermal efficiency but specific work output remains unchanged.

  3. Incorporation of intercooling process in a multi- stage compression increases specific work output but the heat input also increases.

  4. Incorporation of intercooling process in a multi-stage compression system increases specific work output, but the heat addition remains un-changed.

  Which of the above statements are correct?
  A)
  1 and 3             done clear
  B)
  1 and 4 done clear
  C)
  2 and 3             done clear
  D)
  2 and 4 done clear
  View Solution play_arrow

• question_answer30)
  This stagnation pressure rise in a centrifugal compressor stage takes place:
  A)
  Only in the diffuser done clear
  B)
  In the diffuser and impeller done clear
  C)
  Only in the impeller done clear
  D)
  Only in the inlet guide vanes. done clear
  View Solution play_arrow

• question_answer31)
  Consider the following statements:

  1.  Intercooling is effective only at lower pressure- ratios and high turbine inlet temperatures.

  2.  There is very little gain in thermal efficiency when intercooling is used without the benefit of regeneration.

  3.  With higher value of 'y' and \[{{c}_{p}}\] of the working fluid, will net power output of Brayton cycle will increase.

  Of these statements:
  A)
  1, 2 and 3 are correct done clear
  B)
  1 and 2 are correct done clear
  C)
  1 and 3 are correct   done clear
  D)
  2 and 3 are correct done clear
  View Solution play_arrow

• question_answer32)
  Large clearance volume in reciprocating compressor results in
  A)
  Reduced volume flow rate done clear
  B)
  Increased volume flow rate done clear
  C)
  Lower suction pressure done clear
  D)
  Lower delivery pressure done clear
  View Solution play_arrow

• question_answer33)
  In a reciprocating air compressor the compression work per kg of air
  A)
  Increases as clearance volume increases done clear
  B)
  Decreases as clearance volume increases done clear
  C)
  is independent of clearance volume done clear
  D)
  Increases with clearance volume only of multi-stage compressor done clear
  View Solution play_arrow

• question_answer34)
  Consider the following statements:

  When air is to be compressed to reasonably high pressure, it is usually carried out by multistage compressor with an intercooler between the stages because

  1. Work supplied is saved

  2. Weight of compressor is reduced.

  3. More uniform torque is obtained leading to the reduction in the size of flywheel.

  4. Volumetric efficiency

  Of the four statements listed above:
  A)
  1 alone is correct done clear
  B)
  2 and 4 are correct done clear
  C)
  1, 2 and 3 are correct done clear
  D)
  1, 2, 3 and 4 are correct done clear
  View Solution play_arrow

• question_answer35)
  Shielding in a nuclear reactor is generally done to protect against:
  A)
  Excess electrons done clear
  B)
  X-rays done clear
  C)
  A-and P-rays done clear
  D)
  Neutron and gamma rays done clear
  View Solution play_arrow

• question_answer36)
  In a centrifugal compressor assuming the same overall dimensions, blade inlet angle and rotational speeds, which of the following bladings will give the maximum pressure rise?
  A)
  Forward curved blades done clear
  B)
  Backward curved blades done clear
  C)
  Radial blades done clear
  D)
  All three types of bladings have the same pressure rise. done clear
  View Solution play_arrow

• question_answer37)
  Under which one of the following sets of conditions will a supersonic compressor have the highest efficiency?
  A)
  Rotor inlet velocity is supersonic and exit velocity subsonic; stator inlet velocity is subsonic and exit velocity is subsonic. done clear
  B)
  Rotor inlet velocity is supersonic and exit velocity subsonic; stator inlet velocity is supersonic and exit velocity is subsonic. done clear
  C)
  Rotor inlet velocity is supersonic and exit velocity supersonic; stator inlet is supersonic and exit velocity is subsonic. done clear
  D)
  Rotor inlet velocity is supersonic and exit velocity supersonic; stator inlet velocity is subsonic and exit velocity is Subsonic done clear
  View Solution play_arrow

• question_answer38)
  The energy released in the fission of one U-235 nucleus approximately:     
  A)
  100 MeV                       done clear
  B)
  200 MeV done clear
  C)
  300 MeV                       done clear
  D)
  400 MeV done clear
  View Solution play_arrow

• question_answer39)
  The critical value of Mach number for a subsonic airfoil is associated with sharp increase in drag due to local shock formation and its interaction with the boundary layer. A typical value of tills critical Mach number is of the order of
  A)
  0.4 to 0.5                      done clear
  B)
  0.75 to 0.85 done clear
  C)
  1.1 to 1.3                      done clear
  D)
  1.5 to 2.0 done clear
  View Solution play_arrow

• question_answer40)
  Consider the following statements:

  Blowdown is necessary on boilers, because

  1. The boiler water level is lowered rapidly in case it accidentally rises too high.

  2. The precipitated sediment or sludge is removed while the boiler is in service.

  3. The concentration of suspended solids in the boiler is controlled.

  Of these statements:
  A)
  1, 2 and 3 are correct done clear
  B)
  1 and 2 are correct done clear
  C)
  3 alone is correct    done clear
  D)
  1 and 3 are correct done clear
  View Solution play_arrow

• question_answer41)
  In a centrifugal compressor, the highest Mach number leading to shockwave in the fluid flow occurs at:
  A)
  Diffuser inlet radius done clear
  B)
  Diffuser outlet radius done clear
  C)
  Impeller inlet radius done clear
  D)
  Impeller outlet radius done clear
  View Solution play_arrow

• question_answer42)
  A double acting steam engine with a cylinder diameter of 19 cm and a stroke of 30 cm has a cut-off of 0.35. The expansion ratio for this engine is nearly:
  A)
  1.05                              done clear
  B)
  2.85 done clear
  C)
  6.65                              done clear
  D)
  10.05 done clear
  View Solution play_arrow

• question_answer43)
  For a multistage compressor, the polytropic efficiency is:
  A)
  The efficiency of all stages combined together done clear
  B)
  The efficiency of one stage done clear
  C)
  Constant throughout for all the stages. done clear
  D)
  A direct consequence of the pressure ratio. done clear
  View Solution play_arrow

• question_answer44)
  Which one of the following is the effect of blade shape on performance of centrifugal compressor?
  A)
  Backward curved blade has poor efficiency done clear
  B)
  Forward curved blades has higher efficiency done clear
  C)
  Backward curved blades lead to stable performance done clear
  D)
  Forward curved blades produce lower pressure ratio. done clear
  View Solution play_arrow

• question_answer45)
  Surging basically implies:
  A)
  Unsteady, periodic and reversed flow done clear
  B)
  Forward motion of air at a speed above sonic velocity done clear
  C)
  The surging action due to the blast of blade shap on in a compressor. done clear
  D)
  Forward movement of aircraft. done clear
  View Solution play_arrow

• question_answer46)
  Which one of the following types of compressors is mostly used for supercharging of I.C. engines?
  A)
  Radial flow compressor done clear
  B)
  Axial flow compressor done clear
  C)
  Roots blower done clear
  D)
  Reciprocating compressor done clear
  View Solution play_arrow

• question_answer47)
  Phenomenon of choking in compressor means:
  A)
  No flow of air. done clear
  B)
  Fixed mass flow rate regardless of pressure ratio. done clear
  C)
  Reducing mass flow rate with increase in pressure ratio done clear
  D)
  Increased inclination of the chord with air steam. done clear
  View Solution play_arrow

• question_answer48)
  The optimum intermediate pressure p, for a gas turbine plant operating between pressure limits \[{{p}_{1}}\] and \[{{p}_{2}}\] with perfect intercolling between the two stages of compression (with identical isentropic efficiency) is given by:
  A)
  \[{{p}_{1}}={{p}_{2}}-{{p}_{1}}\]                 done clear
  B)
  \[{{p}_{i}}={{p}_{i}}=\frac{1}{2}({{p}_{1}}+{{p}_{2}})\] done clear
  C)
  \[{{p}_{i}}=\sqrt{{{p}_{1}}.{{p}_{2}}}\]                     done clear
  D)
  \[{{p}_{i}}=\sqrt{p_{2}^{2}.p_{1}^{2}}\] done clear
  View Solution play_arrow

• question_answer49)
  Once through boiler is named as such because:
  A)
  Flue gas passes only in one direction           done clear
  B)
  There is no recirculation of water done clear
  C)
  Air as sent through the same direction done clear
  D)
  Steam is sent out only in one direction done clear
  View Solution play_arrow

• question_answer50)
  Centrifugal compressors are suitable for large discharge and wider mass flow range, but at a relatively low discharge pressure of the order of 10 bars, because of:
  A)
  Low pressure ratio done clear
  B)
  Limitation of size of receiver done clear
  C)
  Large speeds done clear
  D)
  High compression index      done clear
  View Solution play_arrow

• question_answer51)
               Given: \[{{v}_{w\,2}}=\] velocity of whirl at outlet         

  \[{{u}_{2}}=\]Peripheral velocity of the blade tips

  The degree of reaction in a centrifugal compressor equal to:

  A)
  \[1-\frac{{{v}_{w\,2}}}{2{{u}_{2}}}\]               done clear
  B)
  \[1-\frac{{{u}_{2}}}{2{{v}_{w\,2}}}\] done clear
  C)
  \[1-\frac{2{{v}_{w\,2}}}{{{u}_{2}}}\]               done clear
  D)
  \[1-\frac{{{v}_{w\,2}}}{{{u}_{2}}}\] done clear
  View Solution play_arrow

• question_answer52)
  Match List-I with List-II (pertaining to blower performance) and select the correct answer using the codes given below the lists: 

  List-I		List-II
  A.	Slip	1.	Reduction of whirl velocity
  B.	Stall	2.	Fixed mass flow rate regardless of pressure ratio
  C.	Choking	3.	Flow separation
  		4.	Flow area separation

  Codes:   
  A)
  A\[\to \]4, B\[\to \]3, C\[\to \]2 done clear
  B)
  A\[\to \]1, B\[\to \]3, C\[\to \]2 done clear
  C)
  A\[\to \]4, B\[\to \]1, C\[\to \]3 done clear
  D)
  A\[\to \]2, B\[\to \]3, C\[\to \]4   done clear
  View Solution play_arrow

• question_answer53)
             In a gas turbine cycle, the turbine output is 600 kJ/kg, the compressor work is 400 kJ/kg and the heat supplied is 1000 k/kg. The thermal efficiency of this cycle is:                                 
  A)
  80%                              done clear
  B)
  60%         done clear
  C)
  40%                              done clear
  D)
  20%          done clear
  View Solution play_arrow

• question_answer54)
  In a single-stage open-cycle gas turbine, the mass flow through the turbine is higher than the mass flows through compressor, because:
  A)
  The specific volume of air increases by use of intercooler done clear
  B)
  The temperature of air increases in the reheater done clear
  C)
  The combustion of fuel takes place in the combustion chamber done clear
  D)
  Specific heats at constant pressure for incoming air and exhaust gases are different done clear
  View Solution play_arrow

• question_answer55)
  Reaction turbine discharges 3 m/s of water under a head of 10 m with an overall efficiency of 92%. The power developed is:
  A)
  295.2 kW                       done clear
  B)
  237.0 kW done clear
  C)
  271.0 kW                       done clear
  D)
  265.2 kW done clear
  View Solution play_arrow

• question_answer56)
  In steam turbine terminology, diaphragm refers to:
  A)
  Separating wall between rotors carrying nozzles done clear
  B)
  The ring of guide blades between rotors done clear
  C)
  A partition between low and high pressure dies done clear
  D)
  The flange connecting the turbine exit to the condenser done clear
  View Solution play_arrow

• question_answer57)
  Gas turbine develops 120 kJ of work while the compressor absorbed 60 kJ of work and the heat supplied is 200 kJ. If regenerator which would recover  40% of the heat in the exhaust were used, then the increase in the overall thermal efficiency would be:
  A)
  10.2%               done clear
  B)
  8.6% done clear
  C)
  6.9%                 done clear
  D)
  5.7% done clear
  View Solution play_arrow

• question_answer58)
  In a two-stage compressor with ideal intercooling, for the work requirement to be minimum, the intermediate pressure \[{{p}_{i}}\] in terms of condenser and evaporator pressure \[{{p}_{c}}\] and \[{{p}_{e}}\] respectively is:
  A)
  \[pi={{p}_{c}}{{p}_{e}}\]                    done clear
  B)
  \[pi={{p}_{i}}=\sqrt{{{P}_{a}}{{P}_{e}}}\] done clear
  C)
  \[pi={{P}_{i}}=\sqrt{{{\text{P}}_{\text{a}}}\text{/}{{\text{P}}_{\text{e}}}}\]  done clear
  D)
  \[pi={{\text{p}}_{\text{c}}}\text{/}{{\text{p}}_{\text{e}}}\] done clear
  View Solution play_arrow

• question_answer59)
  A four-stage compressor with perfect intercooling between stages compresses air from 1 bar to 16 bar. The optimum pressure in the last intercooler will be:
  A)
  6 bar                 done clear
  B)
  8 bar done clear
  C)
  10 bar               done clear
  D)
  12 bar done clear
  View Solution play_arrow

• question_answer60)
  In the centrifugal air compressor design practice, the value of polytropic exponent of compression is generally taken as:
  A)
  1.2                                done clear
  B)
  1.3 done clear
  C)
  1.4                                done clear
  D)
  1.5 done clear
  View Solution play_arrow

• question_answer61)
  The turb machine used to circulate refrigerant in large refrigeration plant is:
  A)
  A centrifugal compressor done clear
  B)
  A radial turbine done clear
  C)
  An axial compressor done clear
  D)
  An axial turbine done clear
  View Solution play_arrow

• question_answer62)
  The energy transfer process is:
  A)
  Continuous in a reciprocating compressor and intermittent in an axial compressor done clear
  B)
  Continuous in an axial compressor and intermittent in a reciprocating compressor done clear
  C)
  Continuous in both reciprocating and axial compressors done clear
  D)
  Intermittent in both reciprocating and axial compressors. done clear
  View Solution play_arrow

• question_answer63)
  In an axial flow co impresser stage, air enters and leaves the stage axially. If the whirl component of the air leaving the rotor is half the mean peripheral velocity of the rotor Wades, then the degree of reaction will be:
  A)
  1.00                              done clear
  B)
  0.75 done clear
  C)
  0.50                              done clear
  D)
  0.25 done clear
  View Solution play_arrow

• question_answer64)
  If an axial flow compressor is designed for a constant velocity through all stages, then the area of annulus of the succeeding stages will:
  A)
  Remain the same done clear
  B)
  Progressively decrease done clear
  C)
  Progressively increase done clear
  D)
  Depend upon the number of stages. done clear
  View Solution play_arrow

• question_answer65)
  What will be the shape of the velocity triangle at the exit of a radial bladed centrifugal impeller, taking into account slip?
  A)
  Right-angled done clear
  B)
  Isosceles done clear
  C)
  All angles less than \[90{}^\circ \] done clear
  D)
  One angle greater than \[90{}^\circ \] done clear
  View Solution play_arrow

• question_answer66)
  In a De Laval nozzle expanding superheated steam from 10 bar to 0.1 bar, the pressure as the minimum cross-section will be:
  A)
  3.3 bar              done clear
  B)
  5.46 bar done clear
  C)
  8.2 bar              done clear
  D)
  9.9 bar done clear
  View Solution play_arrow

• question_answer67)
  Which one of the following statements is the?
  A)
  In a multi-stage compressor, adiabatic efficiency less than stage efficiency done clear
  B)
  In a multi-stage turbine; adiabatic efficiency is less than the stage efficiency done clear
  C)
  Preheat factor for a multistage compressor is greater than one done clear
  D)
  Preheat factor does not effect the multistage compressor performance done clear
  View Solution play_arrow

• question_answer68)
  At constant efficiency, the horse power of a fan is:
  A)
  Proportional to rpm done clear
  B)
  Proportional to \[{{(rpm)}^{2}}\] done clear
  C)
  Proportional to \[{{(rpm)}^{3}}\] done clear
  D)
  A polynomial function of rpm done clear
  View Solution play_arrow

• question_answer69)
  At the eye tip of a centrifugal impeller, blade velocity is 200 m/s while the uniform axial velocity at the inlet is 150 m/s. If the sonic velocity is 300 m/s, then the inlet Mach number of the flow will be:
  A)
  0.50                              done clear
  B)
  0.66 done clear
  C)
  0.83                              done clear
  D)
  0.87 done clear
  View Solution play_arrow

• question_answer70)
  A gas turbine works on which one of the following cycles?
  A)
  Brayton             done clear
  B)
  Rankine done clear
  C)
  Stirling               done clear
  D)
  Otto done clear
  View Solution play_arrow

• question_answer71)
  Reheating in a gas turbine:
  A)
  Increases the compressor work done clear
  B)
  Decreases the compressor work done clear
  C)
  Increases the turbine work done clear
  D)
  Decreases the turbine work done clear
  View Solution play_arrow

• question_answer72)
  A 3 - stage reciprocating compressor has suction pressure of 1 bar delivery pressure of 27 bar. For minimum work of compression, the delivery pressure of 1st stage is:
  A)
  14 bar               done clear
  B)
  9 bar done clear
  C)
  5.196 bar                       done clear
  D)
  3 bar done clear
  View Solution play_arrow

• question_answer73)
  Consider the following factors:

  1.  Cylinder size

  2.  Clearance ratio

  3.  Delivery pressure

  4. Compressor shaft power.

  The factors which affect the volumetric efficiency of a single-stage reciprocating air compressor would include:
  A)
  1 and 2             done clear
  B)
  3 and 4 done clear
  C)
  2 and 3             done clear
  D)
  1 and 4 done clear
  View Solution play_arrow

• question_answer74)
  A three-stage Rateau turbine is designed in such a manner that the first two stages develop equal power with identical velocity diagram while the third one develops more with higher blade speed. In such a multistage turbine the blade ring diameter:
  A)
  Is the same for all the three stages done clear
  B)
  Gradually increases from the first to the third done clear
  C)
  Of the third stage is greater than that of the first two stages, done clear
  D)
  Of the third stage is less than that of the first two stages. done clear
  View Solution play_arrow

• question_answer75)
  In Centrifugal compressor terminology, vaneless space refers to the space between:
  A)
  The inlet and blade inlet edge done clear
  B)
  Blades in the impeller done clear
  C)
  Diffuser exit and volute casing done clear
  D)
  Impeller tip and diffuser inlet edge done clear
  View Solution play_arrow

• question_answer76)
  If the static temperature rise in the rotor and stator respectively are \[\Delta {{T}_{A}}\] and \[\Delta T,B\] then degree of reaction in an axial flow compressor is given by:
  A)
  \[\frac{\Delta {{T}_{A}}}{\Delta {{T}_{B}}}\]               done clear
  B)
  \[\frac{\Delta {{T}_{A}}}{\Delta {{T}_{A}}+\Delta {{T}_{B}}}\] done clear
  C)
  \[\frac{\Delta {{T}_{B}}}{\Delta {{T}_{a}}+\Delta {{T}_{B}}}\]                       done clear
  D)
  \[\frac{\Delta {{T}_{B}}}{\Delta {{T}_{A}}}\] done clear
  View Solution play_arrow

• question_answer77)
  Consider the following statements relating to a closed gas turbine cycle:

  1. The cycle can employ monatomic gas like helium instead of air to increase the cycle efficiency if other conditions are the same.

  2. The efficiency of heat exchanger increases with the use of helium

  3. The turbine blades suffer higher corrosion damages.

  4.  Higher output can be obtained for the same size.

  Which of these statements are correct?
  A)
  1, 2 and 3                      done clear
  B)
  1, 2 and 4 done clear
  C)
  2, 3 and 4                      done clear
  D)
  1, 3 and 4 done clear
  View Solution play_arrow

• question_answer78)
  The capacity of an air compressor is specified as \[10\,\,{{\text{m}}^{\text{3}}}\text{/min}\text{.}\] It means that the compressor is capable of:
  A)
  Supplying \[3\,{{\text{m}}^{\text{3}}}\] of compressed air per minute done clear
  B)
  Compressing \[3\,{{\text{m}}^{\text{3}}}\] of free air per minute done clear
  C)
  Supplying \[3\,{{\text{m}}^{\text{3}}}\] of compressed air at NTP done clear
  D)
  Compressing \[3\,{{\text{m}}^{\text{3}}}\] of standard air per minute done clear
  View Solution play_arrow

• question_answer79)
  A two-stage compressor takes in air at 1.1 bars and, discharges at 20 bars. For maximum efficiency, the intermediate pressure is:                        
  A)
  10.55 bars                     done clear
  B)
  7.33 bars            done clear
  C)
  5.5 bars             done clear
  D)
  4.7 bars          done clear
  View Solution play_arrow

• question_answer80)
    Which one of the following pairs of features and compressors type is not correctly matched? 
  A)

  Intake and delivery ports compression is attainedby back flow and internal compression cylindrical rotor set to eccentric casing

  :

  Vane compressor

  done clear
  B)

  Intermittent discharge requires receiver, produces compressor high pressure, slow speed and lubrication problems

  :

  Reciprocating Compressor

  done clear
  C)

  Continuous flow, radial flow, handles large volume, much higher speed and fitted into design of aero-engines

  :

  Centrifugal compressor

  done clear
  D)

  Successive pressure drops through contracting compressor passages, blades are formed from a number of circular arcs, axial flow

  :

  Axial compressor

  done clear
  View Solution play_arrow

• question_answer81)
               Consider the following statement:

  The volumetric efficiency of a reciprocating compressor can be enhanced by

  1.  Heating the intake air

  2. Decreasing the clearance volume

  3.  Cooling the intake air

  Which of these statements is/are correct?      
  A)
  1 alone              done clear
  B)
  1 and 2                                 done clear
  C)
  2 and 3             done clear
  D)
  3 alone     done clear
  View Solution play_arrow

• question_answer82)
                               Reciprocating compressors are provided with:
  A)
  Simple disc/plate valve                   done clear
  B)
  Poppet valve                           done clear
  C)
  Spring-loaded disc valve                 done clear
  D)
  Solenoid valve    done clear
  View Solution play_arrow

• question_answer83)
                        Consider the following statements:

  In centrifugal compressors, there is a tendency of increasing surge when

  1. The number of diffuser vanes is less than the number of impeller vanes

  2. The number of diffuser vanes is greater than the number of impeller vanes

  3. The number of diffuser vanes is equal to the number of impeller vanes

  4. Mass flow is greatly in excess of that corresponding to Lbs design mass flow

  Which of these statements is/are correct?
  A)
  1 and 4             done clear
  B)
  2 alone done clear
  C)
  3 and 4 done clear
  D)
  2 and 1 done clear
  View Solution play_arrow

• question_answer84)
  In an axial flow compressor design, velocity diagrams are constructed from the experimental data of aerofoil cascades. Which one of the, following statements in this regard is correct?
  A)
  Incidence angle of the approaching air is measured from the trailing edge of the blade done clear
  B)
  \[\delta \] Is the deviation angle between the, angle of incidence and tangent to the amber line done clear
  C)
  The deflection of the gas steam while passing through the cascade is given by \[\varepsilon ={{\alpha }_{1}}-{{\alpha }_{2}}\] done clear
  D)
  \[\varepsilon \] Is the sum of the angle of incidence and camber less any deviation angle, i.e. \[\varepsilon =i+\theta -\delta \] done clear
  View Solution play_arrow

• question_answer85)
  The efficiency of a simple gas turbine can be improved by using a regenerator, because the:
  A)
  Work of compression is reduced done clear
  B)
  Heat required to be supplied is reduced done clear
  C)
  Work output of the turbine is increased done clear
  D)
  Heat rejected is increased done clear
  View Solution play_arrow

• question_answer86)
  Consider the following statements: The reheat cycle helps to reduce

  1. Fuel consumption

  2. Steam flow

  3. The condenser size

  Which of these statements are correct?
  A)
  1 and 2             done clear
  B)
  1 and 3 done clear
  C)
  2 and 3             done clear
  D)
  1, 2 and 3 done clear
  View Solution play_arrow

• question_answer87)
  For a two-stage reciprocating air compressor, the suction pressure is 1.5 bar and the delivery pressure is 54 bar. What is the value of the ideal intercooler pressure?
  A)
  6 bar                 done clear
  B)
  9 bar done clear
  C)
  27.75 bar                       done clear
  D)
  \[\frac{9}{\sqrt{12}}\] bar done clear
  View Solution play_arrow

• question_answer88)
  If n the polytropic index of compressor and \[\frac{{{p}_{2}}}{{{p}_{1}}}\] is the pressure ratio for a three-stage compressor with ideal intercoolling, the on total work of three stage is:
  A)
  \[\frac{3n}{(n-1)}{{p}_{1}}{{v}_{1}}\,\left\{ {{\left( \frac{{{p}_{2}}}{{{p}_{1}}} \right)}^{(n-1)/n}}-1 \right\}\] done clear
  B)
  \[\frac{n}{(n-1)}{{p}_{1}}{{v}_{1}}\,\left\{ {{\left( \frac{{{p}_{2}}}{{{p}_{1}}} \right)}^{(n-1)/n\,3}}-1 \right\}\] done clear
  C)
  \[\frac{n}{(n-1)}{{p}_{1}}{{v}_{1}}\,\left\{ {{\left( \frac{{{p}_{2}}}{{{p}_{1}}} \right)}^{(n-1)/n}}-1 \right\}\] done clear
  D)
  \[\frac{3n}{(n-1)}{{p}_{1}}{{v}_{1}}\,\left\{ {{\left( \frac{{{p}_{2}}}{{{p}_{1}}} \right)}^{(n-1)/\,3\,n}}-1 \right\}\] done clear
  View Solution play_arrow

• question_answer89)
  The flow in the vaneless space between the impeller exit and diffuser inlet of a centrifugal compressor can be assumed as:
  A)
  Free vortex                     done clear
  B)
  Forced vortex done clear
  C)
  Solid body rotation         done clear
  D)
  Logarithmic spiral done clear
  View Solution play_arrow

• question_answer90)
  The effect of friction on flow of steam through a nozzle is to:
  A)
  Decrease the mass flow rate and to increase the wetness at the exit done clear
  B)
  Increase the mass flow rate and to increase the exit temperature done clear
  C)
  Decrease the mass flow rate and to decrease the wetness of the steam done clear
  D)
  Increase the exit temperature, without any effect on the mass flow rate. done clear
  View Solution play_arrow

• question_answer91)
  Consider the following statements regarding the axial flow in an air compressor :

  1.  Surging is a local phenomenon while stalling affects the entire compressor.

  2.  Stalling is a local phenomenon while surging affects the entire compressor.

  3. The pressure ratio of an axial compressor stage is smaller than that of a centrifugal compressor stage.

  Of these statements:
  A)
  1, 2 and 3 are correct done clear
  B)
  1 and 2 are correct done clear
  C)
  2 and 3 are correct   done clear
  D)
  1 and 3 are correct. done clear
  View Solution play_arrow

• question_answer92)
  The thermal efficiency of a gas turbine cycle with regeneration in terms of \[{{T}_{3}}\] (maximum temperature),\[{{T}_{1}}\] (minimum temperature) \[{{r}_{p}}\] (pressure ratio) and \[k-\left( \frac{{{c}_{p}}}{{{c}_{v}}} \right)\] is given by:
  A)
  \[1-\frac{{{T}_{1}}}{{{T}_{3}}}{{r}_{p}}^{\left( \frac{k}{k-1} \right)}\]                       done clear
  B)
  \[1-\frac{{{T}_{1}}}{{{T}_{3}}}{{r}_{p}}^{\left( \frac{k}{k-1} \right)}\] done clear
  C)
  \[1-\frac{{{T}_{3}}}{{{T}_{1}}}{{r}_{p}}^{\left( \frac{k-1}{k} \right)}\]                       done clear
  D)
  \[1-\frac{{{T}_{1}}}{{{T}_{3}}}{{r}_{p}}^{\left( \frac{k-1}{k} \right)}\] done clear
  View Solution play_arrow

• question_answer93)
  The pressure rise in the impeller of centrifugal compressor is achieved by:
  A)
  The decrease in volume and diffusion action the done clear
  B)
  Centrifugal action and decrease in volume done clear
  C)
  The centrifugal and diffusion action done clear
  D)
  The centrifugal and push-pull action. done clear
  View Solution play_arrow

• question_answer94)
  Compared to axial compressors centrifugal compressors are more suitable for:
  A)
  High head, low How rate done clear
  B)
  Low head, low flow rate done clear
  C)
  Low head, high how rate done clear
  D)
  High head, high flow rate done clear
  View Solution play_arrow

• question_answer95)
  Stalling of blades in axial-flow compressor is the phenomenon of:
  A)
  Air stream blocking the passage done clear
  B)
  Motion of air at sonic velocity done clear
  C)
  Unsteady, periodic and reversed flow done clear
  D)
  Air stream not able to follow the blade contour done clear
  E)
  (e) The same turbine can be used for both plants done clear
  View Solution play_arrow

• question_answer96)
  What is the ratio of the static enthalpy rise in the rotor to the static enthalpy rise in the stage of an axial flow compressor defined as?
  A)
  Power input factor done clear
  B)
  Flow coefficient done clear
  C)
  Temperature coefficient done clear
  D)
  Degree of reaction done clear
  View Solution play_arrow

• question_answer97)
  A gas turbine plant working on Joule cycle produces 4000 kW of power. If its work ratio is 40%, what is the power consumed by the compressor?
  A)
  2400 kW                        done clear
  B)
  4000 kW done clear
  C)
  6000 kW                        done clear
  D)
  8000 kW done clear
  View Solution play_arrow

• question_answer98)
  The suction pressure is 1 bar and delivery pressure is 125 bar. What is the ideal intermediate pressure at the end of first stage for a 3-stage air compressor?
  A)
  25 bar               done clear
  B)
  5 bar done clear
  C)
  10 bar               done clear
  D)
  20 bar done clear
  View Solution play_arrow

• question_answer99)
  Which one of the following is correct? In a gas turbine cycle with regeneration
  A)
  Pressure output increases done clear
  B)
  Work output decreases done clear
  C)
  Thermal efficiency increases done clear
  D)
  Heat input increases done clear
  View Solution play_arrow

• question_answer100)
  A centrifugal compressor is suitable for which of the following?
  A)
  High pressure ratio, low mass flow done clear
  B)
  Low pressure ratio, low mass flow done clear
  C)
  High pressure ratio, high mass flow done clear
  D)
  Low pressure ratio, high mass flow done clear
  View Solution play_arrow

• question_answer101)
  Which one of the following types of impeller vanes are most commonly used in centrifugal type compressors?
  A)
  Forward curved   done clear
  B)
  Radial done clear
  C)
  Backward curved            done clear
  D)
  Tangential done clear
  View Solution play_arrow

• question_answer102)
  Given: \[{{\eta }_{s}}=\] Stage efficiency, \[{{\eta }_{n}}=\] Nozzle efficiency, \[{{\eta }_{s}}=\] Blade efficiency, Which one of the following is correct?
  A)
  \[{{\eta }_{n}}={{\eta }_{b}}={{\eta }_{s}}\]              done clear
  B)
  \[{{\eta }_{b}}={{\eta }_{s}}{{\eta }_{n}}\] done clear
  C)
  \[{{\eta }_{s}}\times {{\eta }_{n}}\times {{\eta }_{s}}=1\]         done clear
  D)
  \[{{\eta }_{s}}={{\eta }_{s}}{{\eta }_{n}}\] done clear
  View Solution play_arrow

• question_answer103)
  Which one of the following is correct? For incompressible flow a diverging section acts as a diffuser for upstream flow which is:
  A)
  Subsonic only done clear
  B)
  Supersonic only done clear
  C)
  Body subsonic and supersonic done clear
  D)
  Sonic done clear
  View Solution play_arrow

• question_answer104)
  Roots blower is an example of:
  A)
  Reciprocating (positive displacement) compressor done clear
  B)
  Rotary (positive displacement) compressor done clear
  C)
  Centrifugal compressor done clear
  D)
  Axial compressor done clear
  View Solution play_arrow

• question_answer105)
  Irrotational flow occurs when:                   
  A)
  Flow takes place in a duct of uniform cross- section at constant mass flow rate             done clear
  B)
  Streamlines are curved                       done clear
  C)
  There is no net rotation of the fluid element about its mass center.                              done clear
  D)
  Fluid element does not undergo any change in size or shape.    done clear
  View Solution play_arrow

• question_answer106)
                            A single-stage impulse with a diameter of 120 cm runs at 3000 rpm. If the blade speed ratio is 0.42, then the inlet velocity of steam will be:              
  A)
  79 m/s               done clear
  B)
  188 m/s            done clear
  C)
  \[45{}^\circ \]m/s                      done clear
  D)
  900 m/s          done clear
  View Solution play_arrow

• question_answer107)
    In an ideal impulse turbine, the:                
  A)
  Absolute velocity at the inlet of moving blade is equal to that at the outlet                     done clear
  B)
  Relative velocity at the inlet of the moving blade is equal to that at the outlet                    done clear
  C)
  Axial velocity at the inlet is equal to that at the outlet done clear
  D)
  Whirl velocity at the inlet is equal to that at the outlet done clear
  View Solution play_arrow

• question_answer108)
  For a Parson's reaction turbine if a, and \[{{\alpha }_{2}}\] are fix angles at inlet and exit respectively and \[{{\beta }_{1}}\] and \[{{\beta }_{2}}\] are the moving blade angles at entrance and  respectively, then:                            
  A)
  \[{{\alpha }_{1}}={{\alpha }_{2}}\,\,and\,\,{{\beta }_{1}}={{\beta }_{2}}\] done clear
  B)
  \[{{\alpha }_{1}}={{\alpha }_{1}}\,\,and\,\,{{\alpha }_{2}}={{\beta }_{2}}\] done clear
  C)
  \[{{\alpha }_{1}}<{{\beta }_{1}}\,\,and\,\,{{\alpha }_{2}}={{\beta }_{2}}\] done clear
  D)
  \[{{\alpha }_{1}}={{\beta }_{2}}\,\,and\,\,{{\beta }_{1}}={{\alpha }_{2}}\] done clear
  View Solution play_arrow

• question_answer109)
  The isentropic enthalpy drop in moving blade is two - thirds of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be:    
  A)
  0.4                                done clear
  B)
  0.6               done clear
  C)
  0.66                              done clear
  D)
  1.66            done clear
  View Solution play_arrow

• question_answer110)
  In a fully trubulent flow through a rough pipe, the friction factor \['f'\] is (Re is the Reynolds number and \[{{\xi }_{s}}/D\] is relative roughness):              
  A)
  A function of Re done clear
  B)
  A function of Re and \[{{\xi }_{s}}/D\] done clear
  C)
  A function of \[{{\xi }_{s}}/D\] done clear
  D)
  Independent of Re and \[{{\xi }_{s}}/D\] done clear
  View Solution play_arrow

• question_answer111)
   In a boundary layer developed along the flow, the pressure decreases in the downstream direction. The boundary layer thickness would:
  A)
  Tend to decrease done clear
  B)
  Remain constant done clear
  C)
  Increase rapidly  done clear
  D)
  Increase gradually done clear
  View Solution play_arrow

• question_answer112)
  Which one of the following statements is true of flow around a submerged body?
  A)
  For subsonic, non-viscous flow, the drag is zero done clear
  B)
  For supersonic flow the drag coefficient is dependent equally on Mach number and Reynolds number done clear
  C)
  The lift and drag coefficient of an aerofoil is independent of Reynolds number               done clear
  D)
  For incompressible flow around an aerofoil, the profile drag is the sum of form drag and skin Friction drag. done clear
  View Solution play_arrow

• question_answer113)
  If 'n' variables in a physical phenomenon contained 'm' fundamental dimensions, then the variables can be arranged into:
  A)
  N dimensionless terms done clear
  B)
  M dimensionless terms done clear
  C)
  \[(n-m)\] Dimensionless terms done clear
  D)
  (n + m) dimensionless terms done clear
  View Solution play_arrow

• question_answer114)
  Given power 'P' of a pump, the head 'H' and the discharge 'Q' and the specific weight \['\omega '\] of the liquid, dimensional analysis would lead to the result that 'P' is proportional to:
  A)
  \[{{H}^{1/2}}\,\,{{Q}^{2}}w\]                       done clear
  B)
  \[{{H}^{1/2}}\,\,Q\,w\] done clear
  C)
  \[H\,{{Q}^{1/2}}\,w\]               done clear
  D)
  \[H\,Q\,w\] done clear
  View Solution play_arrow

• question_answer115)
  A 1: 20 model of a spillway dissipates 0.25 hp. The corresponding prototype horsepower dissipated will
  A)
  0.25                              done clear
  B)
  5.00 done clear
  C)
  447.20              done clear
  D)
  8944.30 done clear
  View Solution play_arrow

• question_answer116)
  If the stream function is given by \[\psi =3xy,\] then the velocity at a point (2, 3) will be:
  A)
  7.21 unit                        done clear
  B)
  10.82 unit done clear
  C)
  18 unit              done clear
  D)
  54 unit done clear
  View Solution play_arrow

• question_answer117)
  Efficiency of nozzle governed turbines is affected mainly by losses due to:
  A)
  Partial admission done clear
  B)
  Throttling done clear
  C)
  Interstage pressure drop done clear
  D)
  Condensation in last stages. done clear
  View Solution play_arrow

• question_answer118)
  Stability of a freely floating object is assured if its centre of:
  A)
  Buoyancy lies below its Centre of gravity done clear
  B)
  Gravity coincides with its Centre of buoyancy done clear
  C)
  Gravity lies below its metacenter done clear
  D)
  Buoyancy lies below its metacenter done clear
  View Solution play_arrow

• question_answer119)
  A vertical sluice gate, 2.5 m wide and weighing 500 kg is held in position due to horizontal force of water on one side and associated friction force. When the water level drops down to 2 m above the bottom of the gate, the gate just starts sliding down. The coefficient of friction between the gate and the supporting structure is:
  A)
  0.20                              done clear
  B)
  0.10 done clear
  C)
  0.05                              done clear
  D)
  0.02 done clear
  View Solution play_arrow

• question_answer120)
  The reheat cycle in steam power plant is mainly adopted to
  A)
  Improve thermal efficiency done clear
  B)
  Decrease the moisture content in low pressure stages to a safe value done clear
  C)
  Decrease the capacity of condenser done clear
  D)
  Recover the waste heat of toiler done clear
  View Solution play_arrow