Railways NTPC (Technical Ability) Internal Combustion Engine (ICE) Question Bank

done Internal Combustion Engine (ICE) Total Questions - 120

• question_answer1)
  Consider the following statements regarding the advantages of fuel injection over carburetion in S.I. engines:

  1. Higher power output and increased volumetric efficiency.

  2. Simple and inexpensive injection equipment.

  3. Longer life of injection equipment.

  4. Less knocking and reduced tendency for back-fire.

  Select the correct answer using the codes given below:

  Codes:
  A)
  1, 2 and 3                      done clear
  B)
  1, 2 and 4 done clear
  C)
  2 and 3             done clear
  D)
  1 and 4 done clear
  View Solution play_arrow

• question_answer2)
  Match List I with List II and select the correct answer using the codes given below the lists:

  List-I (Elements of a complete  carburettor)		List-II (Rich-mixture requirement)
  A.	Idling system	1.	To compensate for dilution of charge
  B.	Economiser	2.	Fore cold starting
  C.	Acceleration pump	3.	For meeting maximum power range of operation
  D	Choke	4.	For meeting rapid opening of throttle

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

• question_answer3)
  Match List I with List II and select the correct answer using the codes given below the lists:

  List-I (S.I. Engine Problem)		List-II (Characteristic of fuel responsible for the problem)
  A.	Cold starting	1.	Front end volatility
  B.	Carburettor icing	2.	Mid-range  volatility
  C.	Crankcase dilutions	3.	Tail end volatility

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

• question_answer4)
  Besides mean effective pressure, the data needed for determining the indicated power of an engine would include:
  A)
  Piston diameter, length of stroke and calorific value of fuel done clear
  B)
  Piston diameter, specific fuel consumption and calorific value of fuel done clear
  C)
  Piston diameter, length of stroke and speed of rotation done clear
  D)
  Specific fuel consumption, speed of rotation and torque done clear
  View Solution play_arrow

• question_answer5)
  For a typical automobile C.I engine, for conditions of increasing engine speed match List I with List II and select the correct answer using codes given below the lists:

  List-I (Performance parameter)		List-II (Tendency, qualitatively)
  A.	Power output	1.	Increasing and then decreasing
  B.	Torque	2.	Decreasing and then increasing
  C.	Brake specific fuel consumption	3.	Increasing throughout the range
  		4.	Decreasing throughout the range

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

• question_answer6)
  Consider the following statements:              

  I. The performance of an S.I. engine can be improved by increasing the compression ratio.

  II. Fuels of higher octane number can be employed at higher compression ratio.

  Of these statements                        
  A)
  Both I and II are true done clear
  B)
  Both I and II are false done clear
  C)
  I is true but II is false done clear
  D)
  I is false but II is true done clear
  View Solution play_arrow

• question_answer7)
  Match List I with List II and select the correct answer using the codes given below the lists:        

  List-I (Name of propellant)		List-II (Type of propellant)
  A.	Nitric acid	1.	Fuel
  B.	Hydrogen	2.	Monopropellant
  C.	Fuming nitric acid hydrazine	3.	Oxidizer
  D.	Methyl nitrate-methyl alcohol	4.	Compounded liquid mono propellant
  		5.	Hypergolic propellant

  Codes:
  A)
  A\[\to \]2, B\[\to \]1, C\[\to \]4, D\[\to \]5 done clear
  B)
  A\[\to \]1, B\[\to \]2, C\[\to \]5, D\[\to \]4 done clear
  C)
  A\[\to \]3, B\[\to \]1, C\[\to \]5, D\[\to \]4 done clear
  D)
  A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]5 done clear
  View Solution play_arrow

• question_answer8)
  The object of providing masked inlet valve in the air passage of compression-ignition engines is to
  A)
  Enhance flow late              done clear
  B)
  Control air flow       done clear
  C)
  Induce primary swirl done clear
  D)
  Induce secondary turbulence done clear
  View Solution play_arrow

• question_answer9)
  Which one of the following events would reduce the volumetric, efficiency of a vertical compression ignition engine?
  A)
  Intel valve closing after bottom head Centre done clear
  B)
  Inlet valve closing before bottom dead Centre done clear
  C)
  Inlet valve opening top dead Centre done clear
  D)
  Exhaust valve closing after top dead Centre done clear
  View Solution play_arrow

• question_answer10)
  As compared to air standard cycle, in actual working, the effect of variation in specific heats is to:
  A)
  Increase maximum pressure and maximum temperature. done clear
  B)
  Reduce maximum pressure and maximum temperature. done clear
  C)
  Increase maximum pressure and decrease maximum temperature. done clear
  D)
  Decrease maximum pressure and Increase maximum temperature. done clear
  View Solution play_arrow

• question_answer11)
  For the same maximum pressure and heat input:
  A)
  The exhaust temperature of petrol engine is more than that of diesel engine done clear
  B)
  The exhaust temperature of diesel engine is more than that of petrol engine done clear
  C)
  The exhaust temperature of dual cycle engine is less than that of diesel engine done clear
  D)
  The exhaust temperature of dual cycle engine is more than that of petrol engine done clear
  View Solution play_arrow

• question_answer12)
  In Orsat apparatus:
  A)
  Carbon dioxide is absorbed in cuprous chloride done clear
  B)
  Carbon monoxide is absorbed in caustic potash solution done clear
  C)
  Oxygen is absorbed in pyrogallic acid done clear
  D)
  Nitrogen is absorbed in hot nickel chrome compound done clear
  View Solution play_arrow

• question_answer13)
  In solid propellants rockets, ammonium picrate is usually added as:
  A)
  An additive                    done clear
  B)
  An inhibitor done clear
  C)
  A darkening agent           done clear
  D)
  a plasticizer done clear
  View Solution play_arrow

• question_answer14)
  A turbo prop is preferred to turbo jet because:
  A)
  It has high propulsive efficiency at high speeds done clear
  B)
  It can fly at supersonic speeds done clear
  C)
  It can fly at high elevations done clear
  D)
  It has high power for take off done clear
  View Solution play_arrow

• question_answer15)
  The air fuel ratio for idling speed of an automobile petrol engine is closer to:
  A)
  10 : 1 done clear
  B)
  15 : 1 done clear
  C)
  17 : 1 done clear
  D)
  21 : 1 done clear
  View Solution play_arrow

• question_answer16)
  Which of the following statements is "true"?
  A)
  The term "KNOCK" is used for on identical phenomenon in a spark ignition and compression ignition engine done clear
  B)
  "KNOCK" is a term associated with a phenomeno a taking place in the early part of combustion in a spark ignition engine done clear
  C)
  "KNOCK" is a term associated with a phenomenon taking place in the early part of combustion in a spark ignition engine and the later part of combustion in a compression ignition engine done clear
  D)
  None of the above done clear
  View Solution play_arrow

• question_answer17)
  The essential function of the carburettor in a spark ignition engine is to:
  A)
  Meter the fuel into air stream and amount dictated by the load and speed done clear
  B)
  Bring about mixing of air and fuel to get a homogeneous mixture done clear
  C)
  Vaporize the fuel done clear
  D)
  Distribute fuel uniformly to all cylinders in a multi-cylinder engine and also vaporize it. done clear
  View Solution play_arrow

• question_answer18)
  Match List I with List II and select the correct answer using the codes given below the lists:

  List-I		List-II
  A.	Pre-combustion chamber	1.	Compression swirl
  B.	Turbulent chamber	2.	Masked inlet valve
  C.	Open combustion chamber	3.	Spark ignition
  D.	F-head combustion chamber	4.	Combustion induced swirl
  		5.	M-chamber

  Codes:
  A)
  A\[\to \]4, B\[\to \]5, C\[\to \]3, D\[\to \]2 done clear
  B)
  A\[\to \]1, B\[\to \]3, C\[\to \]5, D\[\to \]2 done clear
  C)
  A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]5 done clear
  D)
  A\[\to \]4, B\[\to \]1, C\[\to \]2, D\[\to \]3 done clear
  View Solution play_arrow

• question_answer19)
  Consider the following statements comparing I.C. engines and gas turbines:

  1. Gas turbines are simple, compact and light in weight.

  2. Complete expansion of working substance is possible in I.C. engines and not in gas turbines.

  3. There is flexibility in the design of different components of gas turbines as different processes take place in different components.

  4. Even low grade fuels can be burnt in gas turbines.

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

• question_answer20)
  Which of the following factors increase detonation in the SI engine?

  1. Increase spark advance.

  2. Increased speed.

  3. Increased air-fuel ratio beyond stoichiometric strength.

  4. Increased compression ratio.

  Select the correct answer using the codes given below:

  Codes:
  A)
  1 and 3             done clear
  B)
  2 and 4 done clear
  C)
  1, 2 and 4                      done clear
  D)
  1 and 4 done clear
  View Solution play_arrow

• question_answer21)
  Reference fuels for knock rating of SI engine fuels would include:
  A)
  Iso-octane and alpha-methyl naphthalene. done clear
  B)
  Normal octane and aniline done clear
  C)
  Iso-octane and n-hexane done clear
  D)
  n-heptane and is-octane done clear
  View Solution play_arrow

• question_answer22)
  Consider the following measures:

  1. Increasing the compression ratio.

  2. Increasing the intake air temperature.

  3. Increasing the length to diameter ratio of the cylinder.

  4. Increasing the engine speed.

  The measures necessary to reduce the tendency to knock in CI engines would include:
  A)
  1, 2 and 3                      done clear
  B)
  1, 2 and 4 done clear
  C)
  1, 3 and 4                      done clear
  D)
  2, 3 and 4 done clear
  View Solution play_arrow

• question_answer23)
  Match List I with List II and select the correct answer using the codes given below the Lists:

  List-I (Operating condition)		List-II (Approximate air fuel ratio)
  A.	Idling	1.	16
  B.	Part load operation	2.	10
  C.	Full load	3.	12.5
  D.	Cold start	4.	3

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

• question_answer24)
  Generally, in Bosch type fuel injection pumps, the quantity of fuel is increased or decreased with change in load, due to change in:
  A)
  Timing of start of fuel injection done clear
  B)
  Timing of end fuel injection done clear
  C)
  Injection pressure of fuel done clear
  D)
  Velocity of flow of fuel done clear
  View Solution play_arrow

• question_answer25)
  If the approximate average mean pressures during induction, compression, power and exhaust strokes of an internal combustion engine are respectively \[\text{15}\,\,\text{k}\,\text{N/}{{\text{m}}^{\text{2}}}\] below atmosphere 200\[k\,\text{N/m}\]  above atmosphere, \[\text{1000}\,\,\text{k}\,\text{N/}{{\text{m}}^{\text{2}}}\] above atmosphere and \[20\,\,\text{N/}{{\text{m}}^{\text{2}}}\] above atmosphere, then the resultant mean effective pressure, in \[k\,\text{N/}{{\text{m}}^{\text{2}}},\] is:
  A)
  765                               done clear
  B)
  795 done clear
  C)
  800                               done clear
  D)
  805 done clear
  View Solution play_arrow

• question_answer26)
  An automatic expansion valve is required to maintain constant:
  A)
  Pressure in the evaporator done clear
  B)
  Temperature in the freezer                    done clear
  C)
  Pressure in the liquid line                       done clear
  D)
  Temperature in the condenser done clear
  View Solution play_arrow

• question_answer27)
                  Which one of following quantities is assumed constant for an internal combustion engine while estimating its friction power by extrapolation through Willan's line?                                 
  A)
  Brake thermal efficiency                   done clear
  B)
  Indicated thermal efficiency                done clear
  C)
  Mechanical efficiency                     done clear
  D)
  Volumetric efficiency        done clear
  View Solution play_arrow

• question_answer28)
                 Excessive pressure drop in liquid line in a refrigerating system causes:                                 
  A)
  High condenser pressure                     done clear
  B)
  Flashing of the liquid refrigerant              done clear
  C)
  Higher evaporator pressure                   done clear
  D)
  Under cooling of the liquid refrigerant     done clear
  View Solution play_arrow

• question_answer29)
     If V is the jet velocity Vo is the Vehicle velocity, the propulsive efficiency of a rocket is given by:
  A)
  \[\frac{2\,\left( {{\text{V}}_{\text{0}}}\text{/}{{\text{V}}_{\text{1}}} \right)}{1+\left( \frac{{{V}_{0}}}{{{V}_{1}}} \right)}\]                        done clear
  B)
  \[\frac{\left( {{\text{V}}_{\text{0}}}\text{/}{{\text{V}}_{\text{1}}} \right)}{1+{{\left( \frac{{{V}_{0}}}{{{V}_{1}}} \right)}^{2}}}\] done clear
  C)
  \[\frac{{{V}_{0}}}{{{V}_{0}}+{{V}_{1}}}\]               done clear
  D)
  \[\frac{{{V}_{1}}}{{{V}_{0}}+{{V}_{1}}}\]     done clear
  View Solution play_arrow

• question_answer30)
  Match List I with List II in respect of a chemical rocket engine and select the correct answer using the codes given below the List:                   

  List-I		List-II
  A.	Ethyl alcohol	1.	Liquid oxidizer
  B.	Nitrocellulose	2.	Liquid fuel
  C.	Ammonium perchlorate	3.	Solid oxidizer
  D.	Hydrogen peroxide	4.	Solid fuel

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

• question_answer31)
  Match List I with List II and select the correct answer using the codes given below the lists: 

  List-I (Operating mode of SI engine)		List-II (Appropriate air-fuel ratio)
  A.	Idling	1.	125
  B.	Cold starting	2.	9.0
  C.	Cruising	3.	16.0
  D	Maximum power	4.	22.0
  		5.	3.0

  Codes:
  A)
  A\[\to \]2, B\[\to \]4, C\[\to \]5, D\[\to \]1 done clear
  B)
  A\[\to \]1, B\[\to \]3, C\[\to \]4, D\[\to \]2 done clear
  C)
  A\[\to \]5, B\[\to \]2, C\[\to \]1, D\[\to \]3 done clear
  D)
  A\[\to \]2, B\[\to \]5, C\[\to \]3, D\[\to \]1 done clear
  View Solution play_arrow

• question_answer32)
  A gas engine has a swept volume of 300 cc and clearance volume of 25 cc. Its volumetric efficiency is 0.88 and mechanical efficiency is 0.90. What is the volume of the mixture taken in per Stroke?
  A)
  248 cc               done clear
  B)
  252 cc done clear
  C)
  264 cc               done clear
  D)
  286 cc done clear
  View Solution play_arrow

• question_answer33)
  Knocking in the SI engine decreases in which one of the following orders of combustion chamber designs?  
  A)
  F head, L head, I head done clear
  B)
  T head, L head, F head done clear
  C)
  I head, T head, F head done clear
  D)
  F head, I head, T head. done clear
  View Solution play_arrow

• question_answer34)
  The two reference fuels used for cetane rating are:
  A)
  Cetane and isooctane done clear
  B)
  Cetane and tetraethyl lead done clear
  C)
  Cetane and n-heptane done clear
  D)
  Cetane and a-methyl naphthalene. done clear
  View Solution play_arrow

• question_answer35)
  Match List I with List II, in respect of SI engines, and select the correct answer by using given below the list:

  List-I		List-II
  A.	Highest useful compression ratio	1.	Ignitable mixture
  B.	Dopes	2.	Knock rating, of fuels
  C.	Limiting mixture strength	3.	Detonation
  D.	Delay period	4.	Chain of chemical reactions in combustion chamber

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

• question_answer36)
  By higher octane number of SI fuel, it is meant that the fuel has:
  A)
  Higher heating value done clear
  B)
  Higher flash point done clear
  C)
  Lower volatility    done clear
  D)
  Longer ignition delay done clear
  View Solution play_arrow

• question_answer37)
  Witch of the following factors would increase the probability of knock in the CI engines?

  1. Long ignition delay of fuel

  2. Low self-ignition temperature of fuel

  3. Low volatility of fuel

  Select the correct answer using the codes given below:

  Codes:
  A)
  1, 2 and 3                      done clear
  B)
  1 and 2 done clear
  C)
  1 and 3             done clear
  D)
  2 and 3 done clear
  View Solution play_arrow

• question_answer38)
  Use of hermetically sealed compressor in a vapour compression refrigeration system results in:
  A)
  Decrease in energy consumption done clear
  B)
  Increase in energy consumption done clear
  C)
  Increase in COP done clear
  D)
  Increase in pressure ratio done clear
  View Solution play_arrow

• question_answer39)
  The correct sequence of the decreasing order of brake thermal efficiency of the three given basic type of IC engines is:
  A)
  4 stroke CI engine, 4 stroke SI engine. 2 stroke SI engine done clear
  B)
  4 stroke SI engine, 4 stroke CI engine, 2 stroke SI engine done clear
  C)
  4 stroke CI engine, 2 stroke SI engine. 4 stroke SI engine done clear
  D)
  2 stroke SI engine, 4 stroke SI engine, 4 stroke CI engine. done clear
  View Solution play_arrow

• question_answer40)
  Keeping other parameters constant brake power diesel engine can he increased by:
  A)
  Decreasing the density of intake air done clear
  B)
  Increasing the temperature of intake air done clear
  C)
  Increasing the pressure of intake air done clear
  D)
  Decreasing the pressure of intake air. done clear
  View Solution play_arrow

• question_answer41)
  The method of determination of indicated power of multi-cylinder SI engine is by the use of:
  A)
  Morse test                      done clear
  B)
  Prony brake test done clear
  C)
  Motorist test                   done clear
  D)
  Heat balance test done clear
  View Solution play_arrow

• question_answer42)
  Consider the following statements: As compared to turboprop, a turbojet

  1. Can operate at higher altitudes

  2. Can operate at higher flight velocities

  3. Is more fuel efficient at lower speeds

  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_answer43)
  Propulsion efficiency of a jet engine is given by(where u is flight velocity and V is jet velocity relative to aircraft):
  A)
  \[\text{2}\,\text{u/}\left( \text{V}\,\,-\,\,\text{u} \right)\]                 done clear
  B)
  \[\left( \text{V}\,\,\text{+}\,\,\text{u} \right)\text{/2}\,\text{u}\] done clear
  C)
  \[\text{2}\,\text{u/}\left( \text{V}\,\,\text{+}\,\,\text{u} \right)\]                  done clear
  D)
  \[\left( \text{V}\,\,-\,\,\text{u} \right)\text{/2}\,\text{u}\] done clear
  View Solution play_arrow

• question_answer44)
  In the Orsat flue gas analyser, ammonia Cal cuprous chloride is used to absorb:
  A)
  \[C{{O}_{2}}\]             done clear
  B)
  CO done clear
  C)
  \[{{O}_{2}}\]                            done clear
  D)
  \[{{N}_{2}}\] done clear
  View Solution play_arrow

• question_answer45)
  List I gives the different terms related to combustion while List II gives the outcome of the events that follow. Match List I with List II and select the correct answer.

  List-I		List-II
  A.	Association	1.	Pseudo shock
  B.	Dissociation	2.	Knock
  C.	Flame front	3.	Endothermic
  D.	Abnormal combustion	4.	Exothermic

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

• question_answer46)
  Which one of the following engines will have heavier flywheel than the remaining ones?
  A)
  40 HP. four-stroke petrol engine running at 1500 rmp. done clear
  B)
  40 H.P. two-stroke petrol engine running at 1500 rmp. done clear
  C)
  40 H.P. two-stroke diesel engine running at 750 rmp. done clear
  D)
  40 H.P. four-stroke diesel engine running at 750 rmp. done clear
  View Solution play_arrow

• question_answer47)
  Consider the following statements: Knock in the SI engine can be reduced by

  1. Supercharging

  2. Retarding the spark.

  3. Using a fuel of long straight chain structure.

  4. Increasing the engine speed.

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

• question_answer48)
  Consider the following statements: The injector nozzle of a CI engine is required to inject fuel at a sufficiently high pressure in order to

  1. be able to inject fuel in a chamber of high pressure at the end of the compression stroke.

  2. Inject fuel at high velocity to facilitate atomization.

  3. Ensure that penetration is not high.

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

• question_answer49)
  Match List I with List II select the correct answer

  List-I (SI engine operating mode)		List-II (Desired air-fuel ratio)
  A.	Idling	1.	13.0
  B.	Cold starting	2.	4.0
  C.	Cruising	3.	16.0
  D.	Full throttle	4.	9.0

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

• question_answer50)
  Compensating jet in carburettor supplies almost constant amount of petrol at all speeds because:
  A)
  The jet area is automatically varied depending on the suction. done clear
  B)
  The flow from the main jet is diverted to the compensating jet with increase in speed. done clear
  C)
  The diameter of the jet is constant and the discharge coefficient is invariant. done clear
  D)
  The flow is produced due to the static heal in the float Chamber. done clear
  View Solution play_arrow

• question_answer51)
  In the context of performance evaluation of I.C. Engine, match List I with List II and select the correct answer

  List-I (Parameter)		List-II (Equipment for measurement)
  A.	Brake power(B.H.P.)	1.	Bomb calorimeter
  B.	Engine speed	2.	Electrical  tachometer
  C.	Calorific value of fuel	3.	Hydraulic dynamometer
  D.	Exhaust emissions	4.	Flame ionisation detector

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

• question_answer52)
  Consider the following statements:            

  In open cycle turbo jet engines used in military aircraft, reheating the exhaust gas from the turbine by burning more fuel is used to increase.

  1. Thrust.

  2. The efficiency of engine.

  3. The range of aircraft.

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

• question_answer53)
                   In a turbo-jet engine, subsequent to heat addition to compressed air, to get the power output, the working substance is expanded in:                   
  A)
  Turbine blades, which is essentially an isentropic process.                                  done clear
  B)
  Turbine blades, which is polytropic process. done clear
  C)
  Exit nozzle, which is essentially an isentropic process.                                  done clear
  D)
  Exit nozzle, which is a constant volume process.  done clear
  View Solution play_arrow

• question_answer54)
                           Consider the following statements relating to rocket engines:                                  

  1. The combustion chamber in a rocket engine is directly analogous to the reservoir of a supersonic wind tunnel.

  2. Stagnation conditions exist at the combustion chamber.

  3. The exit velocities of exhaust gases are much higher than those in jet engines.

  4. Efficiency of rocket engines is higher than that of jet engines.

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

• question_answer55)
                   only rocket engines can be propelled to 'SPACE' because:
  A)
  They can generate very high thrust. done clear
  B)
  They have high propulsion efficiency. done clear
  C)
  These engines can work on several fuels. done clear
  D)
  They are not air-breathing engines. done clear
  View Solution play_arrow

• question_answer56)
  Items given in List I and List II pertain to gas analysis. Match List I with List II and select the correct answer.

  List-I		List-II
  A.	\[C{{O}_{2}}\]	1.	Alkaline pyrogallol
  B.	Orsat apparatus	2.	KOH solution
  C.	CO	3.	Wet analysis
  D.	\[{{O}_{2}}\]	4.	Ammonia-calcurprous chloride
  		5.	Dry analysis

  Codes:
  A)
  A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4 done clear
  B)
  A\[\to \]1, B\[\to \]3, C\[\to \]2, D\[\to \]4 done clear
  C)
  A\[\to \]1, B\[\to \]5, C\[\to \]4, D\[\to \]2 done clear
  D)
  A\[\to \]2, B\[\to \]5, C\[\to \]4, D\[\to \]1 done clear
  View Solution play_arrow

• question_answer57)
  Which of the following factors are responsible formation of \[N{{O}_{X}}\] in spark ignition engine combustion:

  1. Incomplete combustion

  2. High temperature

  3. Availability of answer.

  A)
  2 and 3             done clear
  B)
  1 and 2 done clear
  C)
  1 and 3             done clear
  D)
  1, 2 and 3 done clear
  View Solution play_arrow

• question_answer58)
  The presence of nitrogen in the products of combustion ensures that:
  A)
  Complete combustion of fuel takes place done clear
  B)
  Incomplete combustion of fuel occurs done clear
  C)
  Dry products of combustion are analysed done clear
  D)
  Air is used for the combustion done clear
  View Solution play_arrow

• question_answer59)
  For maximum specific output of a constant volume cycle (Otto cycle):
  A)
  The working fluid should he air done clear
  B)
  The speed should he high done clear
  C)
  Suction temperature should be high done clear
  D)
  Temperature of the working fluid at the end of compression and expansion should be equal done clear
  View Solution play_arrow

• question_answer60)
  A two-stroke engine has a speed of 750 rpm. A four stroke engine having an identical cylinder size runs at 1500 rpm. The theoretical output of the two-stroke engine will:
  A)
  Be twice that of the four-stroke engine done clear
  B)
  Be half that of the four-stroke engine done clear
  C)
  Be the same as that of the four-stroke done clear
  D)
  Depend upon whether it is a C.I. or S.I. engine done clear
  View Solution play_arrow

• question_answer61)
  For same power output and same compression ratio, as compared to two-stroke engines, four-stroke S.I. engines have:
  A)
  Higher fuel consumption done clear
  B)
  Lower thermal efficiency done clear
  C)
  Higher exhaust temperatures done clear
  D)
  Higher thermal efficiency done clear
  View Solution play_arrow

• question_answer62)
  In a SI Engine, which one of the following is the correct order of the fuels with increasing detonation tendency?
  A)
  Paraffins, Olefins, Naphthenes, Aeromatics done clear
  B)
  Aeromatics, Naphthenes, Paraffins, Olefins done clear
  C)
  Naphthenes, Olefins, Aeromatics, Paraffins done clear
  D)
  Aeromatics, Naphthenes, Olefins, Paraffins done clear
  View Solution play_arrow

• question_answer63)
  Consider the following statements: Detonation in the S.I. engine can be suppressed by

  1. Retarding the spark timing

  2. Increasing the engine speed.

  3. Using 10% rich mixture.

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

• question_answer64)
  The pipes and fittings in an ammonia refrigeration system should be made of:
  A)
  Cast street or wrought iron done clear
  B)
  Aluminum done clear
  C)
  Naval brass                                   done clear
  D)
  Copper done clear
  View Solution play_arrow

• question_answer65)
  A sample of moist air is at a temperature T and relative humidity 50%. A part of the moisture is removed adiabatically by using an absorbent. If the heat of adsorption is negligible, the resulting air will have the same:
  A)
  Dry bulb temperature but a lower wet bulb temperature done clear
  B)
  Wet bulb temperature but a higher dry bulb temperature done clear
  C)
  Dry bulb temperature but a higher dry bulb temperature done clear
  D)
  Wet bulb temperature but a lower dry bulb temperature done clear
  View Solution play_arrow

• question_answer66)
  Consider the following statements:

  1. Volumetric efficiency of diesel engines is higher than that of SI engines

  2. When a SI engine is throttled; its mechanical efficiency decreases.

  3. Specific fuel consumption increases as the power capacity of the engine increases.

  4. Inspite of higher compression ratios, the exhaust temperature in diesel engines is much lower than that in SI engines.

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

• question_answer67)
  Consider the following statements about a rocket engine:

  1. It is a very simple in construction and operation.

  2. It can attain very high vehicle velocity.

  3. It can operate for very long duration.

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

• question_answer68)
  In summer air-conditioning, the conditioned air passing through the space undergoes a process of:
  A)
  Sensible cooling done clear
  B)
  Sensible heating done clear
  C)
  Cooling and dehumidification done clear
  D)
  Heating and humidification done clear
  View Solution play_arrow

• question_answer69)
  Which of the following are the assumptions involved in the auto-ignition theory put forth for the onset of knock in SI engines?

  1. Flame velocity is normal before the onset of auto ignition.

  2. A number of end-gas elements auto ignite simultaneously.

  3. Preflame reactions are responsible for preparing the end-gas to ignite.

  Select the correct answer using the codes given below:

  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_answer70)
  Suppose, the mean body surface temperature of a certain unclothed person is \[30{}^\circ C,\] the mean temperature of surrounding surfaces is \[21{}^\circ C\] and the air within the room is at \[32{}^\circ C,\] 90 per cent RH, then the person will lose maximum body heat by:
  A)
  Convection done clear
  B)
  Radiation done clear
  C)
  Mass transfer done clear
  D)
  Convection, radiation mass transfer done clear
  View Solution play_arrow

• question_answer71)
  In some carburettors, meter rod and economizer device is used for:
  A)
  Cold starting                   done clear
  B)
  idling done clear
  C)
  Power enrichment           done clear
  D)
  acceleration done clear
  View Solution play_arrow

• question_answer72)
  Which of the following pairs of engine and performance/characteristic is/are correctly matched?

  1. Turbojet: Efficiency increases with flight speed

  2. SI engine: Lowest specific fuel consumption

  3. Turboprop: Suitable for low flight speeds

  Select the correct answer using the codes given below:

  Codes:
  A)
  1 and 2             done clear
  B)
  2 and 3 done clear
  C)
  1 and 3             done clear
  D)
  2 alone done clear
  View Solution play_arrow

• question_answer73)
  Which one of the following is the correct sequence of the position of the given components in a turboprop?                         
  A)
  Propeller, Compressor, Turbine, Burner done clear
  B)
  Compressor, Propeller, Burner, Turbine done clear
  C)
  Propeller, Compressor, Burner, Turbine     done clear
  D)
  Compressor, propeller. Turbine, Burner    done clear
  View Solution play_arrow

• question_answer74)
  Consider the following statements: The thrust of rocket engine depends upon:                

  1. Effective jet velocity

  2. Weight of the rocket

  3. Rate of propellant consumption

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

• question_answer75)
  Consider the following statements: In a turbojet engine, thrust may be increased by:         

  1. Increasing the jet velocity

  2. Increasing the mass flow rate of air.

  3. After burning of the fuel.

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

• question_answer76)
         The effective jet exit velocity from a rocket is 2700 m/s. The forward flight velocity is 1350 m/s. the propulsive efficiency of the unit is:        
  A)
  200%                done clear
  B)
  100%         done clear
  C)
  66.666%                        done clear
  D)
  33.333%    done clear
  View Solution play_arrow

• question_answer77)
    Consider the following emission of an IC engine:

  (1) CO

  (2) HC

  (3) \[N{{O}_{X}}\]

  (4) Particulates

  Which of these emissions cause photochemical smog?
  A)
  1 and 4             done clear
  B)
  1 and 2       done clear
  C)
  2 and 3             done clear
  D)
  3 and 4     done clear
  View Solution play_arrow

• question_answer78)
    Velocity of flame propagation in the SI engine is maximum for a fuel-air mixture which is: 
  A)
  10% richer than stocihiometric        done clear
  B)
  Equal to stoichiometric                done clear
  C)
  More than 10% richer than stocihiometric done clear
  D)
  10% leaner than stoichiometric     done clear
  View Solution play_arrow

• question_answer79)
       Divided chamber diesel engines use lower injection pressures compared to open chamber engines because:
  A)
  Pintle nozzles cannot withstand high injection pressures                              done clear
  B)
  High air swirl does not require high injection pressures for atomization               done clear
  C)
  High injection pressures may cause over penetration                        done clear
  D)
  High injection pressure causes leakage of the fuel at the pintle     done clear
  View Solution play_arrow

• question_answer80)
                       In a variable speed S.I. Engine, the maximum torque occurs at the maximum:
  A)
  Speed                done clear
  B)
  Brake power                       done clear
  C)
  Indicated power                     done clear
  D)
  Volumetric efficiency          done clear
  View Solution play_arrow

• question_answer81)
         In a domestic refrigerator, a capillary tube controls the flow of refrigerant form the:
  A)
  Expansion valve to the evaporator done clear
  B)
  Evaporator to the thermostat done clear
  C)
  Condenser to the expansion valve done clear
  D)
  Condenser to the evaporator done clear
  View Solution play_arrow

• question_answer82)
  The coefficient of performance (COP) of a refrigerator working as a heat pump is given by:
  A)
  \[{{(COP)}_{heat\,\,pump}}={{(COP)}_{refrigerator}}+2\] done clear
  B)
  \[{{(COP)}_{heat\,\,pump}}={{(COP)}_{refrigerator}}+1\] done clear
  C)
  \[{{(COP)}_{heat\,\,pump}}={{(COP)}_{refrigerator}}-1\] done clear
  D)
  \[{{(COP)}_{heat\,\,pump}}={{(COP)}_{refrigerator}}\] done clear
  View Solution play_arrow

• question_answer83)
  Consider the following steps:

  (1) Starting of compressor.

  (2) Starting of cooling tower pump

  (3) Starting of chiller water pump

  (4) Starting of blower motor of cooling coil

  The correct sequence of these steps in the starting of a central air conditioning plant using chilled water cooling coil is:
  A)
  3, 1, 4, 2                       done clear
  B)
  1, 3, 2, 4 done clear
  C)
  3, 2, 1, 4                       done clear
  D)
  1, 3, 4, 2 done clear
  View Solution play_arrow

• question_answer84)
  March List-I with List-II and select the correct answer using the codes given below the Lists:

  List-I		List-II
  A.	Freon 12	1.	Centrifugal systems
  B.	Freon 22	2.	Low temperature cold storage
  C.	Freon 11	3.	Window type units
  D.	Ammonia	4.	Ice plants

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

• question_answer85)
  The equivalent diameter D of a circular duct corresponding to a rectangular duct having longer side ?a? and shorter side 'b' the same velocity and Pressure drop is given by:
  A)
  \[D=\frac{a+b}{ab}\]                done clear
  B)
  \[D=\frac{ab}{a+b}\] done clear
  C)
  \[D=\frac{\left( a+b \right)}{2ab}\]                      done clear
  D)
  \[D=\frac{2ab}{a+b}\] done clear
  View Solution play_arrow

• question_answer86)
  Consider the following statements: During sensible heating

  1. Moisture content increases

  2. Dry bulb temperature and wet bulb temperature increase.

  3. Dew point remains constant.

  4. Relative humidity increases.

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

• question_answer87)
  Which of the following statements are correct?

  1. The human body can lose heat even if temperature. Is less than the atmospheric temperature.

  2. Relative humidity can be increased by cooling dehumidification.

  3. Warm air increases the rate of radiation of heat from the human body.

  4. Increase in air movement increases the evaporation from the human body.

  Select the correct answer using the codes given below:
  A)
  1 and 4             done clear
  B)
  2 and 4 done clear
  C)
  1 and 3             done clear
  D)
  2 and 3 done clear
  View Solution play_arrow

• question_answer88)
  When the air is passed through an insulated chamber having sprays of water maintained at a temperature higher than the dew point temperature of entering air but lower than its dry bulb temperature, then the air is said to be:
  A)
  Cooled and humidified done clear
  B)
  Cooled and dehumidified done clear
  C)
  Heated and humidified done clear
  D)
  Heated and dehumidified done clear
  View Solution play_arrow

• question_answer89)
  The atmosphere air at dry bulb temperature of \[15{}^\circ C\] enters a heating coil maintained at \[40{}^\circ C.\] The air leaves the heating coil at \[25{}^\circ C.\] The bypass factor of the heating coil is:
  A)
  0.376                done clear
  B)
  0.476 done clear
  C)
  0.6                                done clear
  D)
  0.67 done clear
  View Solution play_arrow

• question_answer90)
  If the specific heats of dry air and water vapour are \[1.00\,\,\text{kJ/kg}-K\] and \[1.88\,\,\text{kJ/kg}-K\] respectively and the humidity ratio is 0.011, then the specific heat of moist air at  \[25{}^\circ C.\] and 50% relative humidity will be
  A)
  \[1.0207\,\,\text{kJ/kg}-K\]           done clear
  B)
  \[1.869\,\,\text{kJ/kg}-K\] done clear
  C)
  \[1.891\,\,\text{kJ/kg}-K\] done clear
  D)
  \[0.9793\,\,\text{kJ/kg}-K\] done clear
  View Solution play_arrow

• question_answer91)
  Consider the following factors:

  (1) Wind velocity

  (2) Type of a activity

  (3) Indoor design conditions

  (4) Door openings

  Occupancy load in cooling load calculation depends upon:
  A)
  1 and 2             done clear
  B)
  1 and 3 done clear
  C)
  1 and 4             done clear
  D)
  2 and 3 done clear
  View Solution play_arrow

• question_answer92)
  Match List-I (Basic components of Aqua ammonia refrigeration system) with List-II functions of the components in the system and select the correct answer using the codes given below the lists:

  List-I		List-II
  A.	Generator	1.	Dehydration
  B.	Analyser	2.	Removal of vapour from strong aqua - ammonia solution
  C.	Rectifier	3.	Producing dry ammonia vapour by removing traces for water particles completely
  D.	Receiver	4.	Storage of high pressure liquid ammonia
  		5.	Formation of liquid ammonia from high pressure vapours.

  Codes:
  A)
  A\[\to \]3, B\[\to \]1, C\[\to \]2, D\[\to \]5 done clear
  B)
  A\[\to \]5, B\[\to \]3, C\[\to \]4, D\[\to \]2 done clear
  C)
  A\[\to \]1, B\[\to \]3, C\[\to \]2, D\[\to \]5 done clear
  D)
  A\[\to \]2, B\[\to \]1, C\[\to \]3, D\[\to \]4 done clear
  View Solution play_arrow

• question_answer93)
  A condenser of refrigeration system rejects heat at rate of 120 kW. While its compressor consumes a power of 30 kW. The coefficient of performance of the system would be:
  A)
  1/4                                done clear
  B)
  1/3 done clear
  C)
  3                                  done clear
  D)
  4 done clear
  View Solution play_arrow

• question_answer94)
  Waste heat can be effectively used in which one of the following refrigeration system?
  A)
  Vapour compression cycle done clear
  B)
  Vapour absorption cycle done clear
  C)
  Air refrigeration cycle done clear
  D)
  Vortex refrigeration system done clear
  View Solution play_arrow

• question_answer95)
  In aircraft, air-refrigeration cycle is used because of:
  A)
  Low unit weight per tonne of refrigeration done clear
  B)
  High heat transfer rate done clear
  C)
  Lower temperature at high-altitudes done clear
  D)
  Higher coefficient of performance done clear
  View Solution play_arrow

• question_answer96)
  A pressure gauge on discharge side of a refrigerant compressor reads too high. The reason could be:

  1. Lack cooling water

  2. Water temperature being high

  3. Dirty condenser surface

  4. Refrigerant temperature being too high

  Of these reasons:
  A)
  1, 2 and 4 are valid         done clear
  B)
  1, 2 and 3 are valid done clear
  C)
  2, 3 and 4 are valid  done clear
  D)
  1, 2 and 4 are valid. done clear
  View Solution play_arrow

• question_answer97)
  Consider the following statements:

  A decrease in evaporator temperature of a vapour compression machine lead to:

  1. An increase in refrigerating effect

  2. An increase in specific volume of vapour

  3. A decrease in volumetric efficiency of compressor

  4. An increase in compressor work.

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

• question_answer98)
  Match List-I with Li.st-II and select the correct answer using the codes given below the lists:   

  List-I		List-II
  A.	Air	1.	Direct contact freezing of food
  B.	Ammonia	2.	Centrifugil compressor system
  C.	Carbon dioxide	3.	Large industrial temperature installation
  D.	Refrigerant-11	4.	Automotive air conditioners.
  		5.	Aircraft refrigeration

  Codes:
  A)
  A\[\to \]4, B\[\to \]3, C\[\to \]1, D\[\to \]2 done clear
  B)
  A\[\to \]5, B\[\to \]3, C\[\to \]1, D\[\to \]2 done clear
  C)
  A\[\to \]2, B\[\to \]4, C\[\to \]3, D\[\to \]5 done clear
  D)
  A\[\to \]5, B\[\to \]3, C\[\to \]2, D\[\to \]1      done clear
  View Solution play_arrow

• question_answer99)
     Consider the following statements:          

  In psychrometry, wet-bulb temperature is a measure enthalpy of moist air, so that in the psychrometric chart:

  1. The constant enthalpy lines are also constant bulb temperature lines.

  2. The wet-bulb and dry bulb temperature are same at any condition

  3. The wet-bulb and dry-bulb temperature are equal at saturation condition.

  Of these statements:                       
  A)
  1 alone is 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_answer100)
                        At 100% relative humidity, the wet bulb temperature is:
  A)
  More than dew point temperature         done clear
  B)
  Same as dew point temperature          done clear
  C)
  Less than dew point temperature          done clear
  D)
  Equal to ambient temperature.     done clear
  View Solution play_arrow

• question_answer101)
         During the adiabatic cooling of moist-air:  
  A)
  DBT remains constant                done clear
  B)
  Specific humidity remains constant      done clear
  C)
  Relative humidity remains constant      done clear
  D)
  WBT remains constant      done clear
  View Solution play_arrow

• question_answer102)
             When a stream of moist air is passed over a cold and dry cooling coil such that no condensation takes place, then the air stream will get cooled along the line of
  A)
  Constant wet bulb temperature           done clear
  B)
  Constant dew point temperature         done clear
  C)
  Constant relative humidity               done clear
  D)
  Constant enthalpy            done clear
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• question_answer103)
          For large tonnage (more than 200 tons) air- conditioning applications, which one of the following types of compressors is recommended?
  A)
  Reciprocating      done clear
  B)
  Rotating done clear
  C)
  Centrifugal                     done clear
  D)
  Screw done clear
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• question_answer104)
  In a cooling tower, "approach" is the temperature difference between the:
  A)
  Hot inlet water and cold outlet water done clear
  B)
  Hot inlet water and WBT done clear
  C)
  Cold outlet water and WBT done clear
  D)
  DBT and WBT. done clear
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• question_answer105)
  When the discharge pressure is too high in refrigeration system, high pressure control is installed to:
  A)
  Stop the cooling fan. done clear
  B)
  Stop the water circulating pump done clear
  C)
  Regulate the flow of cooling water done clear
  D)
  Stop the compressor. done clear
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• question_answer106)
  Consider the following statements:

  In the case of a vapour compression machine, if the condensing temperature of the refrigerant is closer to the critical temperature, then there will be:

  (1) Excessive power consumption

  (2) High compression

  (3) Large volume flow

  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
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• question_answer107)
  Hydrogen is essential in an Electrolux refrigeration system, because:
  A)
  It acts as a catalyst in the evaporator done clear
  B)
  The reaction between hydrogen and ammonia is endothermic in evaporator and exothermic in absorber done clear
  C)
  The cooled hydrogen leaving the heat exchanger cools the refrigerant entering the evaporator done clear
  D)
  It helps in maintaining a low partial pressure for the evaporating ammonia done clear
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• question_answer108)
  In an ideal refrigeration (reversed Carnot) cycle, the condenser and evaporator temperatures are \[27{}^\circ C\] and \[-\,13{}^\circ C\] respectively. The COP of this cycle would be?
  A)
  6.5                                done clear
  B)
  7.5 done clear
  C)
  10.5                              done clear
  D)
  15.0 done clear
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• question_answer109)
  Single-stage vapour compression refrigeration system cannot be used to produce ultralow temperatures because:
  A)
  Refrigerants for ultra-low temperatures are not available done clear
  B)
  Lunbricants for ultra-low temperatures are not available done clear
  C)
  Volumetric efficiency will decrease consider-ably done clear
  D)
  Heat leakage into the system will be excessive done clear
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• question_answer110)
  Vapour absorption refrigeration system works using the:
  A)
  Ability of a substances to get easily condensed or evaporated done clear
  B)
  Ability of a vapour to get compressed or expanded done clear
  C)
  Affinity of a substance for another substance done clear
  D)
  Absorptivity of a substance. done clear
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• question_answer111)
  Two summer air-conditioning systems with non-zero by pass factor are proposed for a room with a known sensible and latent heat load. System A operates with ventilation but system B operates without ventilation. Then the:
  A)
  Bypass factor of system A must be less than the bypass factor of system B done clear
  B)
  Bypass factor of system A must be more than the bypass factor of system B done clear
  C)
  Apparatus dew point for system A must be lower than the apparatus dew point for system B. done clear
  D)
  Apparatus dew point for system A must be higher than the apparatus dew point for system B. done clear
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• question_answer112)
  Evaporative air-cooler used effectively when:
  A)
  dry-bulb temperature is very close to the wet bulb temperature done clear
  B)
  dry-bulb temperature is high and relative humidity is high done clear
  C)
  dry-bulb temperature is low and relative humidity is high done clear
  D)
  dry-bulb temperature is high and the relative humidity is low. done clear
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• question_answer113)
  The minimum temperature to which water can be cooled in a cooling tower is:
  A)
  The dew point temperature of air done clear
  B)
  The wet-bulb temperature of air done clear
  C)
  The dry bulb temperature of air done clear
  D)
  The ambient air temperature done clear
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• question_answer114)
  In a vapour compression refrigeration system, throttle valve is used in place of an expander because:
  A)
  It considerably reduces the system weight. done clear
  B)
  It improves the COP, as the condenser is small. done clear
  C)
  The positive work in isentropic expansion of liquid is very small. done clear
  D)
  It leads to significant cost reduction. done clear
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• question_answer115)
  2000 cc. of air takes \[1{\scriptstyle{}^{1}/{}_{2}}\] minutes to pass through a standard Specimen of sand (5.08 cm high and 5.08 cm in dia.). The manometer indicates pressure as \[5\,\,\text{g/c}{{\text{m}}^{\text{2}}}\text{.}\] In this case the permeability number is:
  A)
  30                                 done clear
  B)
  42 done clear
  C)
  51                                 done clear
  D)
  67 done clear
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• question_answer116)
  A spherical drop of molten metal of radius 2 mm was found to solidify in 10 seconds. A similar drop of radius 4 mm would solidify in:
  A)
  14.14 second                  done clear
  B)
  20 seconds done clear
  C)
  18.30 second                  done clear
  D)
  40 seconds done clear
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• question_answer117)
  The voltage-current characteristics of a DC generator for arc welding is a straight line between an open-circuit voltage of 80 V and short-circuit current of 300A. The generator settings for maximum arc power will be:
  A)
  80 V and 150 A  done clear
  B)
  40 V and 300 A done clear
  C)
  40 V and 150 V  done clear
  D)
  V and 300 A done clear
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• question_answer118)
  Consider the following statements:

  1. Practically all common refrigerants have approximately the same COP and power requirement.

  2. Ammonia mixes freely with lubricating oil and this helps lubrication of compressors.

  3. Dielectric strength of refrigerants is an important property in hermetically sealed compressor units.

  4. Leakage of ammonia can detected by halide torch method.

  Of these statements
  A)
  1, 2, and 4 are correct done clear
  B)
  2 and 4 are correct done clear
  C)
  1, 3 and 4 are correct done clear
  D)
  1 and 3 are correct done clear
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• question_answer119)
  The most commonly used method for the design of duct size is the:
  A)
  Velocity reduction method done clear
  B)
  Equal friction method done clear
  C)
  Static regain method. done clear
  D)
  Dual or double dust method. done clear
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• question_answer120)
  The refrigerant used for absorption refrigerators working heat from solar collectors is mixture of water and :
  A)
  Carbon dioxide done clear
  B)
  Sulphur dioxide done clear
  C)
  Lithium bromide done clear
  D)
  Freon 12 done clear
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